Is Yoosung jealous of the other RFA members? Before I answer that question, I would like to mention that there will be some spoilers for Mystic Messenger in this post. So, proceed with caution. Now then, on with the post! Although Yoosung is one of the more supportive ones in all of the different routes, it does seem like he gets a bit jealous in every other route but his. This can be seen with things like him mentioning being a "forever alone" every time someone mentions the MC's relationship with any of the other characters. He also seems to become attached to the MC very quickly in the first few days leading up to the casual routes, and he even asks the MC if she will wake him up with a kiss if he doesn't wake back up from the "Pass Out After Drinking Caffeine Syndrome" Seven made up. If the MC chooses someone else, he says that person is lucky and complains about having no girlfriend himself. This jealousy can especially be seen in Seven's route, where he mentions in his drunk phone call that "Seven has the princess". Although this is just a small statement, it does show that Yoosung still has some feelings for the MC . Even though this isn't very much evidence for him being jealous of the other characters, there may be a cause for it if he really is jealous. This jealousy might come from him comparing the character to Rika, but it also might come from his "yandere tendencies" that Seven mentioned before. If he really is jealous of the other characters in their routes, it's hard to say why he is. But, these are mostly just my opinions on it anyways. Nonetheless, I hope you guys still like this blog post!