As a young man, he resembled his son and grandson.
50 years prior to the events of the series, as he lied on a bed sick with only one minute left to live, a female Shingami Tamako came to him to guide his soul to the Wheel of Reincarnation about to be reborn as a mackerel. But since he was her type and as he expressed gladness to meet a beautiful Shinigami in the end with a lonely smile that gripped her heart, she fell in love with him instead and broke some laws to extend his lifespan for another 50 years.
They had a son named Sabato, then a grandson named Rinne, whom they raised themselves in the human world, since their daughter-in-law Otome vanished mysteriously and Sabato was not much of a father.
He passed away in spring the year Rinne got enrolled in Sankai High, and went to the Wheel of Reincarnation to be reborn as Mackerel.
The two lived happily together until the end of his extended lifespan.
Rinne had a close bond with his grandfather.
- "Are you a Shinigami? You're beautiful" (あなたは死神か？美しい) – Chapter 6, when he meets Tamako
- His first name was never revealed, although his last name obviously is Rokudo.