A vampire girl who produces too much blood instead of needing it is the setup, but the show is actually about what happens when you fall for someone who has no idea what you are. Karin's attempts to hide her nature while genuinely caring about Kenta create a romance that finds its comedy in the gap between what she feels and what she can say. The show trusts that watching someone silently love another person, constrained by her impossible secret, is enough to carry you through twenty-four episodes.

Karin Maaka is a high schooler from a vampire family in Japan, but she is an odd one even among her own kind. Rather than drinking blood, she has a rare condition that makes her body produce too much of it, leaving her lightheaded and prone to nosebleeds. Roughly once a month she has to release the surplus into random people, who oddly end up livelier and happier for it. Her siblings, the quiet younger Anju and the womanizing older Ren, erase these victims' memories to keep her secret. Then a new classmate, Kenta Usui, transfers in. Around him her blood production surges, and he starts to suspect the truth about her. The show is a supernatural romantic comedy.