Nanase cannot tolerate a man's scent, this is because of a traumatic situation caused by his ex boyfriend - gang rape. Since then, he vomits whenever he smells a man so he always keeps a mask on. One day he bumps into Kei and randomly asks for a one night stand. After having sex, Kei, out of curiosity releases Nanase's mask to which he gets slapped (moreso because Kei smells like his ex). They meet again randomly when Nanase visited an incense shop that Kei owns. They start forming affection to each other and Nanase was able to fall in love with Kei's smell.
Kuyuru