On the way to school, Fumino spots something strange behind the trash can resembling cat ears. Later, Takumi and the others then discover that one of the cake orders was mysteriously eaten up. Ieyasa suspects a little boy for the incident and disbelieves the boy's claims that a large cat is responsible. Realizing what happened in the morning, Fumino tries to find the cat with the boy. Ieyasu and Chise, also after the large cat for their desires (Ieyasu's galge desires and Chise's RPG game "Grand Bravers") compete with Fumino. After Ieyasu, Fumino, and Chise fail to capture the mysterious figure, Otome return home the next day and presents the strange cat, who is a human girl, to Takumi and the others.
梅ノ森学園に通う高校一年生の都築巧は、
洋菓子店「ストレイキャッツ」で、オーナーである姉の乙女と二人暮らし。
幼なじみでクラスメイトの芹沢文乃、梅ノ森学園理事長の孫娘である梅ノ森千世、親友でオタクの菊池家康、
柔術道場の跡取り息子である幸谷大吾郎などに囲まれ、賑やかながらも平穏な日常を過ごしていた。
しかし、そんなある日、結婚記念日用にと注文されていたケーキが盗まれるという事件が発生し……。