On her first day of high school, Kokomi finds herself in an embarrassing predicament when her uniform rips. She is rescued by the strikingly handsome and popular Hajime-senpai, who lends her his jacket. Instantly smitten, Kokomi becomes unable to think of anything else. However, Hajime is always surrounded by adoring girls, making it impossible for her to get close. Her feelings of longing take a dramatic turn when she accidentally discovers his secret: Hajime is an incubus, a supernatural being who feeds on female vitality through intimate acts. Far from being deterred, Kokomi boldly proposes that she become his exclusive source of sustenance, hoping to earn a special place in his heart. What follows is a sweetly erotic romance as the earnest and pure-hearted Kokomi works to seduce the gentle but domineering Hajime. Initially viewing her as just another meal, Hajime finds himself increasingly captivated by her unique flavor and unwavering devotion. As he begins to develop genuine feelings of his own, he grows protective and possessive, even transforming into a cat to stay close to her. Their relationship deepens through a series of intimate encounters and emotional revelations, with Kokomi determined to be the only woman Hajime desires.