A top agent from the devil's training camp was shot and killed by her superior's mutiny. However, she is reborn and becomes the powerful third young lady of the Yan family who is escaping from the extermination……

Murai is a second-year student at Takebe Gakuen High School enrolled in the college preparatory course. His homeroom teacher, Tanaka, summons him to her office after he declares that his post-high school plans are to marry her. Tanaka rejects Murai, telling him that she would never be interested in a boy with long, black hair. Secretly an otaku, she has eyes only for Hitotose, a character from an otome video game. The next day, Murai appears before Tanaka a changed man. Having cut his hair short and dyed it blond, Murai looks exactly like her beloved Hitotose. Tanaka is unable to hide her shock at this sudden development and tries to distance herself from Murai, while Murai presses on in his attempts to romance his teacher.

Naoe-kun, a massage therapist, is about to head home for the day when he's saddled with a rather strange patient. This lovely lady has emerald eyes, pointy ears, and grew up in the forest—everything about her screams "elf," except for one thing: her bodacious body. It turns out she left her world but loves junk food in this one, and now her obsession has caught up with her. Can Naoe-kun help this loveable elf girl lose the weight—and keep it off?