Yūjin Mikotoba was a legal professor at Teito Yūmei University and the father of Susato Mikotoba. In addition to acting as a mentor to Kazuma Asōgi, Yūjin was also the one who invited John Watson to teach in Japan. In the trailer of Dai Gyakuten Saiban 2 Susato is standing over a grave with flowers placed by them, possibly hinting that her father passed away.