Rui, a high school student, is the protagonist of Orange Planet, which revolves around her love life. While delivering a love letter, Rui gets trapped in a fire. Eisuke, the owner of the ablaze apartment building, rescues her and then demands to live in Rui's house as a token of gratitude. However, this results in a predicament for Rui because Tarou, her childhood friend, resides next door and visits her unexpectedly. Can Rui manage to shelter Eisuke without Tarou detecting him?