The first individual who inflicted harm upon me was someone of my own sex. Tsubaki and Kaoru are classmates, while Koutarou treats them kindly like an older sibling. They possess deep-seated desires and an unwavering drive that leaves them exhausted and overwhelmed, both physically and emotionally. Despite this, they pour their hearts and souls into their mundane existence, wholeheartedly devoted to each other. The manga's title, Dousei Ai, signifies "cohabitation" using kanji characters that convey this sense of living together, rather than simply indicating a same-sex relationship.