After years of teasing from her so-called friends, and fed up with her family life at home, reclusive bookworm Ichika takes a risk and summons a demon. She expects an incubus, ready to show her a wild night and erase all her insecurities, even if it's just for a little bit.

Although...she does get an incubus, but he's legit the most introverted demon in all of Hell. Shy, timid, and awkward around girls, he finds himself in a bit of a bind; until the contract is fulfilled, he's unable to leave the mortal realm.

But maybe the mortal realm isn't all that bad, as these two introverts (now forced roommates) learn to enjoy the simple pleasures of life--and perhaps even fall in love in the process.