From Futekiya:

Although he is an assistant manager, Michiya Matsukaze lives in a rickety old apartment and makes do with holes in his socks. He generously treats his subordinates every week and dotes on his pet hamster, Hamuo, although Hamuo is clearly trying to escape at every chance he gets. After one such attempt, Matsukaze runs into Klaus Sakakibara, who falls in love with Matsukaze instantly. With the help of his butler Gramps (a secret magician that can turn animals into human form), Klaus schemes to make Matsukaze his forever. For a financially struggling single man like Matsukaze, what price will he write on his tag? Oh, and... should we go over that power that Gramps possesses...?