Itadaki! Seieki♥ Special / いただきっ! セーエキ♥

Having found a beautiful partner that is well-versed in sexual matters, Kanzaki certainly counts himself lucky. However, reality soon catches up with him, and he wonders why someone as attractive as Mari Setagaya wants to hang out with his mundane self. When Kanzaki reveals his doubts to his girlfriend, Mari worries that he might be getting bored of her. She decides to use her innate charm as a half-succubus and prove to Kanzaki that she has eyes only for him. ...