|“||I'm so glad we're hosting another party! I'm going to do better than last time so that Rika's not disappointed from up there.||”|
—Yoosung, Comment from RFA Orientation Guidebook
Yoosung is one of the Casual Story characters available in Mystic Messenger. Yoosung is a sophomore college student who plays a game called LOLOL and invests too much time into it. Because of that, he does not spend as much time studying for college and neglects his studies. Yoosung is also the cousin of Rika and cannot fully bring himself to believe that she is not alive anymore.
Yoosung is a really nice and lovable person, and is described by the other RFA members as 'a real puppy'. Yoosung cares about people a lot and loves to spend time with others. He is naive and believes things that are told to him more often than not, as shown during several of his interactions with 707. As a result, he is often unforgiving to his naive nature.
Despite his somewhat naive and lighthearted nature, Yoosung is severely depressed after the death of his cousin, Rika, with whom he had a very close relationship with and who he idolized. After the death of Rika, Yoosung lost all interest in his studies and becomes a shut in, rarely leaving for classes and opting instead to play LOLOL in order to cope with the crippling sadness.
During Yoosung's route, 707 states in a phone call with the MC that Yoosung had yandere tenancies, which the MC can expand on if she wants. This reveals Yoosung to be a very possessive person, asking the MC to only text him, to only call and talk to him. The MC can expand on his yandere tenancies which will result in a Bad Ending if she also encourages him to see her as a new Rika.
He is the shortest out of all the male characters, at 171 cm (5'6") and is also the most youthful appearance and age-wise. He has messy, bleached blond hair that he usually keeps out of his eyes with two dark brown hair clips that form an 'X' shape. He has soft violet eyes and a young aura to him in all his photos. His style of clothing usually contains something blue.
It is stated that Yoosung dyed his hair blond in order to get a girlfriend, but also to perhaps look closer in appearance with his cousin who was also blonde. His natural hair colour is a dark brown was usually well kept. Before Rika's death, it is shown in photos that Yoosung would wear more formal clothes before he went to college.
Yoosung grew up in what he calls a typically normal family with his mother, father and sister. It wasn't until the 6th grade that Yoosung met his adoptive cousin, Rika, and began to spend more time with her at his mother's behest.
Eventually, Yoosung began to greatly admire and idolize Rika for her kindness and ability to make others happy; Yoosung admits that he even thought of Rika as a "magician" who could bring happiness to everyone. As a result of his close friendship with his cousin, Yoosung eventually joined the RFA and became friends with the other members.
Rika was a big influence on Yoosung and he decided to apply to SKY University as she had told him to instead of applying to a college closer to him. It was because of Rika that Yoosung decided to become a vet after the death of her beloved Sally, who she loved so greatly.
Rika had a great hand in shaping Yoosung and his future, making him want to become better and to achieve better results in classes and was the reason he wanted to score top results. Her death shook him so greatly that Yoosung states it was a few days before the realization hit him and the tears wouldn't stop coming. After her death, Yoosung became closed off and unmotivated in life, seeing no point in continuing his studies and finding it difficult to cope with the sadness he felt at her death. Eventually, he discovered LOLOL and used it as a means to escape from his depression, neglecting his studies.
When the MC first enters the group chat, Yoosung is initially wary like the other members but is more trusting of the MC. He immediately attempts to be friends with the MC and begins to ask her about her life, before stating that he
believes that the MC is like Rika, his cousin who he had lost two years prior to the story. Yoosung shows himself to be the victim of 707's pranks, which the MC can play along with or try to stop 707's teasing of the younger boy, the latter resulting in obtaining more hearts from Yoosung. The MC shows interest towards Yoosung's hobbies, such as gaming, and can agree that V is suspicious, which will result in them growing closer.
If the MC manages to obtain Yoosung, the two will instantly enter into a very close and cute relationship; out of all the members, Yoosung is the one who calls the most during his route, with nearly after every chat you have with him. Yoosung will almost instantly tell the player his feelings and the two will become a "cutesy" type couple, but it will be a while before Yoosung will ask the MC to be his girlfriend.
During the route, the MC can choose to either encourage Yoosung to drop his studies and that he only needs her, or she can gently support him to give up gaming and to start focusing on his studies. The other members note how much Yoosung has changed in such a short time thanks to MC and her support, but are concerned at how quickly the relationship is progressing. However, it a problem occurs when Yoosung begins to continuously compare the MC to Rika, saying that she shares many traits as her and even going so far as to say that she's "basically" Rika; such an example is when he sends a picture of Rika's dog Sally and, if the MC asks if that is Sally, says that he knew she would "recognize" the dog.
This causes the other members to become concerned for Yoosung and the MC can either encourage Yoosung to think of her as Rika or tell him that while she's grateful that he thinks highly of her, she is not Rika. Encouraging Yoosung to think of her as Rika, will lead to Yoosung to become more possessive and controlling, his "yandere" tenancies coming forth. If the player acts controlling and equally possessive of Yoosung, a Bad Ending will occur when Yoosung steals the address for Rika's apartment to go to the MC; he is initially brought back to sense when he sees that the MC looks nothing like Rika but returns to his "yandere" self and the secret bomb placed within the apartment detonates, killing the two instantly.
If the MC remains supportive and understanding of Yoosung, he eventually realizes that the MC is not Rika, despite the similarities, and that he didn't understand that it was wrong to compare since he thinks both the MC and Rika are amazing people, but will see the MC for who she is, not who she reminds him of. The two enter a brief moment of peace before 707 enters the chatroom to tell the RFA that he had found traces of the hacker during the past few days and that he had managed to change the algorithm of the secret bomb placed in Rika's apartment at her request; if any member tries to enter, of if the MC attempts to leave, the bomb will most likely detonate.
This leaves all the members in a state of shock and disbelief at the fact Rika had requested a bomb be placed in her home and the fact that V knew and allowed the MC to stay there; Yoosung is immediately alarmed and worried for the safety of the MC, becoming distrustful of the RFA and even more hateful towards V. The MC can agree with Yoosung that the RFA can't be trusted, or attempt to calm him down and broker peace between Yoosung and the other members; Yoosung becomes depressed at the prospect of losing the MC as he lost Rika and is furious towards V, who he believes if responsible for Rika's death This anger remains even when 707 recovers the special security system and refuses to give the apartment's address or let the MC leave.
After Yoosung becomes emotionally distant, V visits him suddenly in hopes of cheering him up and to promise that the MC is safe; Yoosung is furious with V and blames him for the death of Rika, saying it was his fault that she died and that he hates him. He blames V and says it is all his fault, for Rika, for putting the MC in danger, and V accepts the blame. In a moment of rare truth, V tells Yoosung that Rika was suffering from mental health issues and had refused treatment for them, and became increasingly unstable before she finally committed suicide. The shock shakes Yoosung and only then does he see V's condition. With his faith in V and the RFA restored, Yoosung visits Jumin and asks him to send more bodyguards to protect the MC and to ask V to receive treatment for him blindness one last time; Jumin complies, but only if Yoosung agrees to take care of a stray kitten he found some time prior.
Despite this, the situation slowly deteriorates within the RFA; Zen is harassed by a stalker outside of his house, and Jaehee receives a suspicious email from Mint Eye. Seven traces the e-mail back to its original location, and decides to go investigate. Wanting to protect the player, Yoosung volunteers to come as well. Before they leave, Yoosung shares one last chat with the MC, talking to her about her likes her for her and not because she reminds him of Rika; it is then he asks the MC to be his "pre-girlfriend", and if they can start officially dating after they deal with the situation with the hacker.
707 and Yoosung arrive at Mint Eye's base and find it be void of people; 707 attempts to recover whatever data that may be left behind and has Yoosung stand guard; there, he has a chance encounter with the hacker, Unknown, and he tells Yoosung to leave so that he can talk to him by himself. It is revealed that 707 recognises the hacker and is clearly flustered by him, becoming ensnared by the hackers words as Unknown attempts to get him to detonate the bomb in Mint Eye and in the apartment. Before 707 can press the button, Yoosung appears and struggles with the hacker, telling 707 to run with the detonator.
The two attempt to run but Yoosung is caught by the hacker without 707's notice and it isn't until later that 707 notices. By then, it's too late and the hacker has gravely injured Yoosung. V arrives in time and manages to save Yoosung and 707 from the hacker, bringing Yoosung to the hospital to get him treated. Not wanting the MC and the others to worry, Yoosung lies about being alright and that the mission went well. It isn't until later at the hospital that it is revealed Yoosung has lost sight in his left eye thanks to the hacker, but it otherwise unharmed.
The other members arrive at the party and find that Yoosung will be arriving with V, much to their surprise. They are unaware of the situation until 707 breaks down in front of the MC and tells her the truth about what happened. The others are shocked and Jumin and Zen decide to head to the hospital before the others notice that Yoosung has arrived at the party, the left side of his face completely bandaged after being released from the hospital.
He makes a speech to the party guests, talking about how much he admired his cousin Rika and the other members of the RFA before confessing his love for the MC, saying that he was glad to have sacrificed himself for her safety. The two then share a kiss in front of the other guests and members, with Yoosung saying he has longed to see her and it's okay now, since she isn't Rika.
Yoosung and Seven share a very close friendship with one another and are the closest out of all the other members; Seven often delights in teasing Yoosung and Yoosung is often naive to Seven's tricks and pranks and is the epitome of being gullible, such as believing Seven when the hacker told him he was going to drink from drinking too much coffee. Seven does, however, apologise if the teasing goes too far and the two genuinely care for each other. In most of the routes, Yoosung even accompanies Seven on his trip to the Mint Eye head quarters as his partner; Seven seems to know a lot about Yoosung and his personality, even revealing to the MC that Yoosung can act possessive and that he has yandere tendencies and that the MC can make Yoosung act on those feelings if she so wishes.
During Yoosung's route, after it is revealed that the MC is trapped with a bomb, Yoosung runs to Seven and begs his friend to help the MC and makes Seven bring him along on the trip to Mint Eye so that he may be able to help the woman he loves in any way he can. There, Yoosung manages to save Seven from being coerced into pulling the trigger on another bomb as well as the one in the apartment but is caught by the Hacker when trying to flee with Seven, resulting in him losing an eye. Seven lies for Yoosung to the others about him being okay but is visibly upset and feels deeply guilty, which results in him in confessing to the others that Yoosung lost an eye in the trip to Mint Eye.
During Jumin's route, Yoosung and Seven work together on revealing Glam and Sarah's past as being sisters and their plan to marry Jumin and Chairman Han in order to get money and, in Zen's route, Yoosung visits Seven after being promised Honey Buddha Chips and Seven even allows him to play LOLOL on his computer in order to keep him entertained.
Out of all the members, Rika was the one whom Yoosung was closest to, mainly because they were cousins; Rika inspired Yoosung and Yoosung greatly looked up to Rika and placed her above all others in his opinion. Rika was the main reason that Yoosung accepted to go to a college far from home and helped him engage in extra curricular activities at school and outside of school. They did many charity events together and Yoosung idolised Rika; when Rika passed away, Yoosung was deeply hurt by her death and became a recluse, having no energy to enjoy the things he once loved doing. Yoosung lost interest in school and spent most of his time playing LOLOL in order to cope with his depression at losing Rika to the point it greatly affected his studies, making him attend summer school in order to catch up.
Because of how greatly he idolised Rika, he blamed V for her death as he believed that V made Rika unhappy in their relationship and found it hard to believe that she was suffering from any mental illness that might have pushed her to commit suicide. Due to this, Yoosung was distrustful towards V and frequently questioned his actions and intentions in the RFA, in the group chat when he wasn't there and even to his face. So great was Yoosung's adoration of Rika was that he began to project onto the MC in hopes of coping with Rika's loss and the MC can either egg on Yoosung's obsession or convince him that she isn't Rika.
In any route that shows that Rika is alive and the leader of the Mint Eye cult, Yoosung refuses to believe that Rika committed so many atrocities and tortured so many people despite the evidence in front of him. In V's route, Yoosung tries to get Seven and the MC through to Rika and tries to convince them that Rika would never hurt him and that he can stop her; Yoosung refuses to see Rika as being the reason for V being in pain and has little sympathy for V, believing that Rika is the true victim of the situation. Eventually, depending on the MC's actions, Rika and Yoosung manage to talk and Yoosung is finally not able to ignore Rika's actions and realises that she has done terrible things to both V and the members of her cult, eventually letting out all th anger he's kept in him since Rika's death and Rika does show some regret for her actions because of Yoosung's response. Depending on the ending, Yoosung is the one to stop Rika from hurting anymore people and no longer tries to excuse her actions.
In the Secret Ending 02, Yoosung and Zen manage to sneak Rika away from having justice done unto her by sending her away to a rehabilitation centre after she became catatonic due to witnessing V's death.
Before Rika's death, it appeared that V and Yoosung had a less antagonistic relationship and were more civil to each other. However, following Rika's supposed death, their relationship broke down and Yoosung began to blame V for Rika's death, becoming distrustful of everything the older man said. Yoosung despised V for not appearing as upset as he was when Rika was announced dead, becoming the main reason he is distrustful of the older man. Despite Yoosung's hatred towards V, V cares deeply for Yoosung and does all he can to help the younger man, letting Yoosung take his anger out on V. He lies to Yoosung, and the others, about Rika's death as he does not want Yoosung to loose the image of Rika that he had in his mind and never told Yoosung about Rika's battle with mental illness because he wanted Rika to be remembered as a bright and happy woman.
During Yoosung's route, Yoosung becomes furious with V with putting the MC in danger and blames him for what has happened and says he doesn't want to lose the MC like he lost Rika. V rushes to Yoosung's home to explain himself and lets Yoosung yell at him before Yoosung notices V's blindness, the two finally overcoming the distrust and bitterness in their relationship. At the end of Yoosung's route, their relationship has healed significantly to what is was before and they are on much more friendly terms.
In V's route, Yoosung's antagonistic feelings remain the same and worsen as it is revealed that Rika is alive; Yoosung refuses to believe that V is a victim of Rika's cruelty and tries to explain that he believes that he thinks V is the real bad guy and Rika is merely a victim, maintaining this point of view throughout much of V's route until, depending on the MC's actions, he can realise how much Rika has changed and that V was right all along and takes his side in the final moments of his route.
V also attended Yoosung's high school gradutation ceremony after Rika's death.
Yoosung and Zen are quite close, with Zen often teasing Yoosung - though not to the same extent of Seven; they share a brotherly bond and Yoosung often is annoyed at how Zen flaunts his good looks, feeling somewhat jealous at how handsome Zen is. Zen often tries to get Yoosung away from video games and stresses the importance of healthy eating and exercise is to Yoosung, to no avail.
During times of stress throughout some of the routes (such as V's route), Yoosung goes to Zen's home and the two comfort each other and keep each other safe, with Zen taking the role of mother hen. Yoosung acts annoyed over Zen's protectiveness but recognises his good intentions.
Zen had also attended Yoosung's high school graduation ceremony after Rika's death.
Yoosung greatly respects Jaehee, and Jaehee often watches out for him and nags him to get his life together frequently, worrying over his gaming addiction and how he doesn't attend class all that often. Jaehee watches out for Yoosung's health and his gaming addiction and tries to get him focusing on his studies, to no avail.
Yoosung brings up at one point that he sometimes sees Jaehee as an older sister looking out for him. In the Christmas special, Yoosung and Jaehee work together for the C&R fundraiser. Jaehee says she is proud of Yoosung for working so hard.
Though they don't share a close bond, Jumin and Yoosung care for each other nonetheless; Yoosung is jealous of Jumin's good looks and money and will often tell the player to stay away from him. Other than that, Jumin and Yoosung are good friends, and it's Jumin who Yoosung turns to in order to protect the MC and Jumin agrees to help, but in return for his help, Yoosung has to take care of a cat that Jumin has taken in earlier during Yoosung's route.
Jumin sees great potential in Yoosung and admits that he had offered him a position at his company some time in the past before Rika's death and, during Yoosung's route, Jumin tells Yoosung that the position is still up for the taking if he really wants it; at one point in Jaehee's route, depending on the MC's actions, Yoosung replaces Jaehee as Jumin's assistant.
Jumin cares for Yoosung and, during Seven's route, he attempts to help Yoosung and gets into contact with Yoosung's mother and though many of the members think Jumin has crossed the line, Yoosung eventually admits that he's thankful towards Jumin for calling his mother and that he missed his mother and was grateful to see her again.
It is also revealed that Jumin had attended Yoosung's high school graduation ceremony after Rika's death.
Yoosung shares a normal and healthy relationship with his mother, but he eventually drifts away from his mother and his family after the death of Rika and moving away from home in order to attend university. Yoosung often complains about his mother and is annoyed when she comes to stay with him for a few days during Seven's route after Jumin got into contact with her, telling her about her son's living situation. Despite being annoyed at his mother, Yoosung eventually admits that he misses his mother and he was grateful that she had stayed with him and enjoyed her visit. Ever since his mother became sick he promised to visit her more often.
There have been moments of friction between mother and son such as when Yoosung's mother attempted to get Yoosung to talk with his aunt and uncle, Rika's mother and father, despite the fact they were cruel to their daughter. Yoosung despises his aunt and uncle's actions towards Rika and is angry towards his mother for how she attempted to get him to get into contact with them.
Sally was Rika's dog and Yoosung is shown to care greatly for her, despite her not being his own dog. Following her death after running out onto the road, it is then that Yoosung decides to become a veterinarian as he was distressed by how upset Rika was at Sally's death after she decided to now get a surgery that would better Sally's eyesight.
During Yoosung's route, Lisa is a kitten that comes under Yoosung's route after Yoosung begged Jumin to help the MC with Jumin's one condition being that Yoosung has to care for the cat; the cat was found by Jumin in a parking lot and for most of Yoosung's route, he attempts to find people to care for the kitten before she is taken in by Yoosung.
During Yoosung's After Ending, Lisa is now under the care of both the MC and Yoosung who are husband and wife.
In the common route, it is hinted that Yoosung has a crush on the MC in the early stages, no matter which route the MC decides to pursue or how much teasing she engages in with Seven or the other members. If the MC pursues any other route, their relationship remains platonic and Yoosung cares for the MC as he does for the other members.
During Yoosung's route, he admits his romantic feelings during the the first day of his route (the earliest in comparison to the other routes) and out of all the members, he calls the MC the most and frequently engages in texting and phone calls with the MC. The MC and Yoosung quickly engage in a very "cutesy" relationship that is noted with alarm by the other members, due to how fast their relationship is progressing. During his route, Yoosung continues to press his belief that the MC is very much like Rika on the MC and the other members and the MC can either agree with Yoosung or attempt to tell him she is flattered, but she is not Rika. At one point, Yoosung even outright states that she is Rika. Depending on the MC's decisions, the MC and Yoosung can die in an explosion in the apartment after the MC doesn't stop Yoosung from engaging in his yandere tendencies and stating that she is Rika.
The MC can pass the game branch and Yoosung begs Jumin to protect the MC with body guards, accompanying Seven on his trip to Mint Eye where he is injured in one eye and loses sight; he worries about the MC to the very end and lie about being hurt to the MC so that the party may continue on as the MC has worked hard to make it happen. In the Good Ending, at the party, after Seven reveals what happened out of guilt, Yoosung appears with one side of his head bandaged and there he reveals his feelings to the MC, eventually kissing her and stating that it's alright because she isn't Rika.