Gunpei Kamafusa seemed to have a violent personality. He hit Naoko Osato with a slap after being slapped by her and tried to grab her by force, even though he immediatelly felt sorry for what he did and begged for forgiveness, saying they didn't need to break up and she shouldn't tell anyone about what happened.
Gunpei is a gardener working for the wealthy Osato family. He was in a relationship with Naoko, the only daughter of the family, and so had to keep their relationship a secret because her over-protective father would never allow them to be together. Gunpei noticed that Naoko was starting to be cold towards him, which leads to him suspecting she may be with someone else. When she tries to break up with him they get into a fight which ends with Gunpei getting pushed towards a golf club. Naoko tells him about how her family decided she would marry Shuichi after she graduates long before meeting Gunpei, without noticing the golf club stuck at the back of Gunpei's head with the impact, killing him.
Shuichi and her father arrive and, despite her efforts, Naoko is unable to contain the continuous and seemingly infinite gush of blood coming out of Gunpei's body to the point of leaving his body decayed few minutes later. Worried that someone finds his body and she's put in jail (as she tried to clean the blood previously, making her a criminal for trying to hide evidence), Naoko hides his body in the ceiling closet in her bedroom in a way his blood would flow into a glass bottle and every morning empties the bottle.
Even though all signs of life had left his body, he seemed to be "continuously dying", Naoko noticed his face would turn back to normal for a few moments if water was sprayed at his face. Still in love with Gunpei, Naoko got pregnant of his corpse and gave birth to two children: a girl and a boy, who also wanted to be a gardener. It is later revealed Gunpei was posessed by the yokai Mutsukabezaka, which happiest moment happens when it dies in front of someone and only purpose is leaving descendants.