Mars (SOURYO Fuyumi)

Kira Aso and Rei Kashino meet when Rei asks Kira for directions to a local hospital one day in the park, but instead of telling him the directions she draws him a map and hands it to him without saying a word. On the back of the directions is a picture Kira drew of a mother and child. On the first day school they are both surprised to find that they are in the same class. Later Rei walks in on their teacher sexually harassing Kira. Rei promises to protect Kira in exchange for a painted version of the sketch that was on the back of the map. He also offers to "lend Kira his body" and she asks him to model for her. All this interaction leads to a very interesting relationship between the two.
Mars Gaiden (Prequel)
The first story, "Namae no nai uma", is a "Mars" prequel telling the first meeting between Rei and Tatsuya and the beginning of their friendship. Moreover, they've also presented other main characters such as Kira and Harumi.
The second and the third stories, "Nemuru Raion" and "1 Karatto no Kajitsu", are oneshots not related to "Mars," and as yet are unscanlated.
The first tells of the strange relationship between Isomu, a guy who pretends to not have any fear, and Ayame, a girl with particular behaviours; on the contrary, the second tells of Nina, who has some family problems, and Rui, her classmate who is interested in a close friend of the her's. But what if he's interested in Nina?