A powerful demon with the ability to read fate. He is one of the four Holy Ones.
He has known Ginshu since he was a child. During their first encounter, Bonten tried to kill him, but found out that it was futile since Ginshu was just a decoy. He was very fond of Ginshu (it was mutual), but unlike Ginshu, he did not like to openly admit it and often spoke to him rudely.
He spent most of the winter as a child playing with Ginshu in various games. However, their relationship changed drastically after the priestess of the Sakigami shrine severely injured Tsuyukusa.
A bloody battle took place, and as Ginshu and Byakuroku killed each other, a deal was made with Heaven, so that Shinshu's power was transferred to Bonten, and he replaced Byakuroku taking his place as Heaven's Seat.
When Bonten first meets Toki he reveals that he has extensive knowledge of modern science and technology. Later on in the series he references Napoleon Bonaparte and at another point sees a boy attached to an IV bag.