Mai Chihara has a reputation that precedes her: with her gothic clothes, jet-black hair and piercing gaze, classmates whisper that she is a "landmine" girl, a look often linked to yandere behavior and shaky temperaments. When high school junior Kuroki ends up seated beside her at the start of a new semester and accidentally catches her attention, a different picture emerges. Rather than the volatile figure the rumors describe, she turns out to be surprisingly sweet, if a little odd. Kuroki cautiously starts learning about her and her unusual quirks, and their everyday interactions mix comedy with budding romance in a slice-of-life school setting, all while asking whether her dark wardrobe hides anything to worry about at all.