Kaoru Sasajima

At the behest of her father, Yui Komori goes to live in a secluded mansion, home to the six Sakamaki brothers—Shuu, Reiji, Ayato, Kanato, Laito, and Subaru—a family of vampires. Though at first the siblings are confused as to why the girl has arrived, they soon realize that she is to be their new "sacrificial bride," not to mention their other, more carnal intentions for her. After meeting the brothers, Yui quickly begins to question why her father would have sent her here and why she feels a strange, new pain in her chest. With each brother more sadistic than the last, Yui's life as a captive takes a harrowing turn in her new home. As her days turn into endless nights, and each brother vows to make her his own, Yui falls deeper and deeper into madness and ecstasy. [Written by MAL Rewrite]

One guy. Five girls. One roof. It's a recycled idea, but it never gets old. Happy Lesson is a kinetic take on an old genre. Chitose shares his house with five ladies. One might think the continued attention of this many girls would be a good thing, but too much attention can prove to be painful. Did I mention they're also instructors at his school (hence the title)? Not only is he the subject of their abuse at home, but at school as well. Even when things finally calm down at night, all the rooms are taken so Chitose must sleep on the couch. (Source: AniDB)