JoJo's Bizarre Adventure

Koichi is asked out by another student in his grade named Yukako Yamagishi. At first, he couldn't hide his joy from being asked out, but quickly has second thoughts when she suddenly loses her temper with him. The next day, she knitted him a sweater, made him lunch, and did other things for him that makes Koichi start to wonder about her. Yukako obssession worsens, and she does the unthinkable.