He comes from Osaka, which explains his funny character.
Years after the events of Angelic Layer, Ichiro worked with Chitose Hibiya, falls in love and marries her, but she could not have children so Ichiro created Elda and Freya, which is named Chii afterwards.
Freya fell in love with Ichiro, and in the anime, she would not tell him and died of sadness. In the manga she confesses her love but he tells her that he loves Chitose. Shortly after the death of Freya, he erased from Chii's memory, then Ichiro gets sick and dies.
In this series he's dead, leaving Chitose Hibiya alone (not much is known about what happened in those years.)