一式さんは恋を知りたい。

Rinna Isshiki made police inspector at seventeen and earned the nickname 'Steel-Faced Rinna', a prodigy at everything except reading her own heart. Whenever the offbeat private detective Meishi Rokutanda is around she gets flustered and slips up, so she does the only logical thing: she proposes a fake relationship with him, strictly as research into love.