I love my psychopath girlfriend

Akira, the popular girl in school notices the school's weirdo, Ukiyo, everyone's questioning...the famous cold prince with the former weirdo? despite all, they had a beautiful time till a series of deaths occurs and things went dark with everyone jumping on Ukiyo TRIGGER WARNING: killings, specific details on body harms and hardcore murder scenes [Disclaimer: the picture used for the cover isn't mine, all credits goes to the rightful owners]