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 comes from a vampire family living quietly in suburban Japan, but she's broken every rule of her kind. Instead of drinking blood, her body produces it in dangerous excess, forcing her to inject the surplus into unsuspecting humans once a month just to survive. She's managed to keep this secret while attending school like a normal teenager, juggling homework and friendships alongside her bizarre condition. Everything shifts when Usui Kenta, a transfer student, joins her class. Suddenly Karin's body goes haywire, pumping out blood at unprecedented rates. The attraction is immediate and overwhelming, and worse, Kenta discovers what she really is. Rather than running away terrified, he becomes entangled in her complicated world, forcing Karin to navigate feelings she's never experienced while keeping her family's existence hidden from the rest of society. The result is a comedy that mixes supernatural absurdity with genuine romance, where the biggest obstacle to their relationship isn't danger or ancient curses, but the simple fact that Karin's literally made of her feelings for him.