Arima Isshin is the Head of the well-known Arima Group. Supposedly his daughter Arima Kanae was going to be the successor but died in a accident with his husband. He adopted Arima Teppei his grandson to be the successor instead of his mother.
He is an old man with white hair [ Probably of his age ] and Black eyes he tends to wear a yukata in Arima Hills but when he was younger, he wears a tuxedo and a hat.
He's a nice and caring man. Some people call him amazing because every time he enters a room the atmosphere changes.
- History with the Houjouin Family
Back then, Arima Isshin is so absorbed by his work everyday that he ignores his own wife. So his wife had an affair with a Houjouin Seika's grandfather so he banned his wife and cut ties with the Houjouin Family. And so he refuses to sell their product until his grandson Arima Teppei is now in charge of the Arima Department Stores.
- History with Hartmann Bazelheim
There was a party that Arima Isshin went to. Hartmann Bazelheim's job was pick pocketing back then. Arima Isshim caught Hartmann's arm and scolded [ more like lectured ] him to stop pick pocketing and find another way to live but Hartmann misunderstood and planned to have revenge on the whole Arima Group but was stop when Arima Teppei opened Hartmann's E\eyes