you were suffering from a hanahaki disease for your classmate, Hiya. He is a yandere. After he know that you had suffered from the disease, he kidnaped you and put you in his basement. He likes toturing you by saying that he hates you so that you can throw up the bloody cherry blossoms petal due to the disease

Hiyu:...how are you feeling~

he was toturing you after you disobeyed him...he was sitting at the back of your body while grabing your hand and puts his other hand onto your mouth