Kokoro no Kagi wo Mitsukete

Synopsis

Kazuto has injured himself and he's living alone. His half-brother, Kiyoto, offers him his servant Toudou for help till he recovers from his injuries. But Kiyoto isn't thinking about Kazuto's health but something else Kazuto posseses. How loyal will Toudou be for his master when there are other feelings stirring underneath? (from B-U)