Aki Aoi and Sora Aoi are a pair of close siblings who have shared an intimate bond since childhood. During their coming of age, they each come to realize the true depth of the love they feel for each other and consummate that love in secret. They keep their younger sister, Nami, Sora’s twin, in the dark about their new relationship. Nami, clueless of what is happening in her household, aims to set her brother up with her best friend, Kana Sumiya. Despite these relationships Nami seems to have feelings for someone near to her too, but keeps them secret.

Nozoki Ana is about an art student named Tatsuhiko Kido. After moving to Tokyo into a new apartment to attend art school he notices a hole in the wall, at first he sees nothing through the hole but one day he sees a girl masturbating so he goes to her apartment to tell her that there is a hole between the wall, he meets her and tries to chat but she walks back to her room so Kido follows her, he trips and he end up being on top of her, so she takes a picture and says to Kido that she will erase the picture if he agrees to expose each other. This begins a life of "peeping" on each other. The story follows Kido through several relationships and his everyday life while he copes with being peeped on by and encouraged to peep on his neighbor; Ikuno Emiru.