Shounen Maid Kuuro-kun: Tenshi no Uta

Having accumulated a massive debt, Curo Kazamiya's father has gone into hiding to evade prosecution. Since his mother passed away several years prior, Curo is forced to sell himself into the service of Miisu Hakuryuuin, a wealthy landowner and businessman.

To the young boy's utmost surprise, his new owner turns out to be a benevolent master who seems to have no intention of punishing him for his father's sins. Instead, he offers Curo the opportunity to become his servant and gradually pay off the debt with his own labor. Curo is quick to agree, considering himself lucky to escape a far worse fate. However, little does he know that Miisu expects him to do tasks beyond the duties of a regular servant.