有馬 平

The main protagonist. Prior to the series, Teppei grew up in a happy family with his mother and father, a noodle shop owner. Coming back from school one day he learns that his parents were killed in an automobile accident. 

He is then picked up by his grandfather, Isshin Arima, who is the owner of the Arima Financial Combine, a very wealthy and perhaps the most powerful industrial group in Japan. Isshin then adopts Teppei with the aim of making him the successor to the Arima corporation (in place of his now-deceased daughter and Teppei's mother) and Teppei is enrolled in the most prestigious private school in Japan. 

He is a good swordsman and excels at quick drawing techniques.