Fed up with being hopelessly single, high schooler Erika makes up a boyfriend to fit in. When her lies start to unravel, her schoolmate Kyoya offers to be her pretend boyfriend--for a price. With no other choice, Erika finds herself at the mercy of a blackhearted prince! But is Kyoya truly as blackhearted as he seems?

It's Erika and Kyoya's first hot springs trip! Erika can't wait to go, but something seems off about Kyoya. When the trip arrives, the pair have a blast sightseeing around town. Back at the inn, however, as the evening draws on and tensions begin to rise, Erika is totally unprepared for what she finds when it's time to finally turn in.