'Hanahaki Disease: in which the victim coughs up flower petals when they suffer from unrequited love. It ends when the beloved returns their feelings (romantic love only; strong friendship is not enough), or when the victim dies. It can be cured through surgical removal, but when the infection is removed, the victim's romantic feelings for their love also disappear.'

Scenario One: 
   It seemed as if Kokichi had been avoiding (Y/C). Whenever they'd enter a room with the purple-haired boy, he would shift awkwardly around you or leave before you could say anything. You didn't understand why. Over the past weeks, you two had grown close together before he'd suddenly avoided and ignored you. (Y/C) had found that they had somewhat enjoyed his company and had actually missed his presence around them. One day as (Y/C) was walking through the hallway, you saw the smaller male duck around the corner, something falling to the floor from out of his pocket. Curiosity getting the best of (Y/C), you bend over and inspect the small item that had fallen from his pocket. It was a flower petal. 

Scenario Two: 
   (Y/C) sat with Kokichi, listening to the leader go on and on about something or the other. (Y/C) had accidentally been tuning him out in favor of looking at his appearance. Kokichi seemed to look a lot tireder and had small eye bags underneath his eyes. His skin seemed to be a sickly pale and his hair was a lot limper than usual. The purple-haired boy glared at you once he realized that you hadn't been listening to his 'exciting tale' of how he had pranked Miu earlier. 

"Hey, that's mean (Y/C)-chan!" The boy crosses his arms. "You were suppose-" You watch helplessly as Kokichi falls into a coughing fit, he quickly turns his head away from you and coughs into his arm. It sounds painful. After the coughing fit is over, he stuffs something into his pocket quickly and grins as if nothing happened. 

Scenario Three:
Make your own!