Kawaikereba Hentai demo Suki ni Natte Kuremasu ka?

After cleaning the Calligraphy Club room, Keiki discovers a love letter on the desk. Excited by the possibility of a relationship, he opens it to find the message "I like you" and a pair of panties. He suspects one of the four girls who helped clean: Sayuki, the club president; Yuika, a library committee member; Mao, a classmate with a tsundere attitude; or Mizuha, his fastidious younger sister. Believing at least three of them could be responsible, Keiki resolves to determine which one sent the letter and the underwear, hoping to find a girlfriend among them.