Nagare is the current head of the Kurosaki clan and the father of Kurosaki Hisoka. As the head, it is his responsibility to bear the ancient god of Kamakura village, Yatonogami, within his body, which torments him both physically and psychologically. This burden is causing him to go blind and seems likely to lead to his death at a relatively young age. Without an heir, once Nagare dies, the formidable god will be free to exact vengeance on the small mountain village.
Earlier in his life, Nagare was married to a woman named Kasane, whom he loved deeply. Together, they had a daughter, also named Hisoka, who was murdered by Nagare's brother Iwao. Grief-stricken, Kasane drowned herself. To cover up her death and possibly in a deranged attempt to replace her—as suggested by Watari—Nagare married Kasane's identical twin sister, Rui, who is the second Hisoka's mother.
After Hisoka was born and grew older, empathic powers began to manifest in him. Nagare and Rui's response was to lock him away in a cell. Flashbacks reveal that multiple people pleaded with Nagare to kill Hisoka, but he refused. Instead, Hisoka died under other circumstances; the cell appears to have been a compromise to appease those frightened by Hisoka's powers.
Nagare seems to regret how he treated his son, going so far as to say he wishes he could "go where [his] children are," but he lacks the resolve to kill himself and allow the village to face Yatonogami's wrath.
He remains embroiled in a blood feud with Iwao, who is bitter about Nagare being the younger brother yet inheriting the title of clan head.
All information cited from the pages of the manga itself.
