Hayasaka and Kirishima are dating, but only because they can’t be with the people they like. Although they’re each other's second choices, they are still attracted to one another, and what started out as a relationship of convenience soon deepens. 

This delicate balance is shaken when Tachibana, Kirishima’s crush, joins the Mystery Research Club. Since the two of them are the only members, this means that Kirishima gets to spend a lot of time alone with her! Could this lead to them getting together? And if so, what will happen with Kirishima and Hayasaka?