Pochi

An amnesiac spirit bound to an old abandoned building. His uneventful days come to an abrupt end with arrival of Izui Fushiki, the tyrannical new owner of the property. Izui is building a private school and he plans to use the ghost, who he dubs "Pochi" to promote it. Since Izui got a hold of Pochi's bones he has no choice but to comply, or else he will never move on to the afterlife. Now he has to gather seven ghosts for the seven mysteries of Togai Academy.

His real name is Hiroya Imanaka (今仲 広哉). His father was a drunkard indebted to yakuza and forced to work for human trafficking to pay off his debts. Hiroya followed him to Togai, where he also met Izui for the first time. Izui invited him to his house when he was hungry and had no place to go. Hiroya promised that they will meet again, but he wasn't able to keep his promise. He ended up being captured by yakuza, raped and choked to death.