Sakamaki Shuu

Shuu is the first and eldest son of the Sakamaki household. He is also the current master of the mansion. Shuu and his younger brother, Reiji, are the sons of Beatrix, second wife of Karlheinz, the Vampire King.
Shuu is usually seen sleeping in the living room or the school's music room. He skips classes often and has been held back several times as a senior in high school. According to other students of the school, Shuu is the owner of the music room.

Apathetic and lazy, Shuu loves nothing but music. It is noted that he is always listening to music, even when taking a bath. Shuu loves classical music, ranging from piano to violin.

He has a lack of motivation and is lazy enough to do almost nothing, seen when Yui needs to persuade him to stay awake and do something for himself. He's somewhat bored with life due to all that happened in his past.

Despite Shuu being the eldest son, he doesn't take any responsibility to look after his five brothers and the house and mostly complains about how he has to "deal with their problems." He mostly pushes this job to Reiji. Shuu is also somewhat of a pervert and usually teases Yui about wearing unattractive panties and bras.