But on his sixteenth birthday, it's not just Rinko's pet that's riling up his allergies (to say nothing of his hormones)! Appearing before him is Himari, a buxom, sword-wielding cat spirit in human guise, who has sworn to protect Yuuto, now the target of vengeful spirits! It's clear that Yuuto's allergies are the least of his problems - he's gonna need Himari's help if he wants to live to see his seventeenth birthday!