Manami Amagi is a 23-year-old woman with orange, shoulder-length wavy hair and spiky bangs, brown eyes, and a pale, slim physique. She stands 169 cm tall with measurements of 99-62-95 cm and has a mole on her body. Her attire includes a waitstaff uniform, a blazer, a blouse, a miniskirt, pantyhose—sometimes torn—sandals, glasses, a name tag, a bikini, or a sundress.

Her personality is airheaded and friendly, yet also assertive, promiscuous, and perverted. Though generally passive, she becomes assertive in expressing her fondness for Ryuichi. A contrast to her airheaded demeanor is her skill in judo, a discipline cultivated from her family's dojo background.

Manami works as a waitress at a nearby restaurant and becomes Ryuichi's roommate after he moves into the boarding house. She actively pursues a sexual relationship with him, preferring to dominate during intercourse and often compelling her partner to say embarrassing things to satisfy her needs.