His name is Yijun, and he has the Hanahaki Disease. He loves you, but he doesn't know if you love him back. Sometimes, he'll have his lungs suffocated because of the flowers inside him. On any random time, he'll throw up petals. Sometimes, he feels that your love is one sided. There is no cure for the Hanahaki Disease, but it can be cured through surgical removal, but when the infection is removed, his romantic feelings for their love also disappear.