Although he had won various film festival awards overseas, Sumiji was not famous in Japan as a director. He founded Studio Daikokuten for the purpose of making a single film in the future. After discovering Kei Yonagi's talent from an audition, he invites her to his studio and guides her to become an actress who will leave an imprint on the history of acting.
Sumiji is a tall, semi-muscular man with tan skin and short, spiky neck-length brown hair with his bangs tied back on top of his head. He also sports a stubbly beard and violet eyes.
In the beginning, Sumiji's attire was rather simple; he wore a plain gray long-sleeved shirt with a v-neck collar and navy blue pants.
Sumiji is a director that takes his job really seriously. It's shown that when he saw Kei's audition, she had great potential to become a movie star.
In the 5th round of acting tryouts, Sumiji is unimpressed by the women that were selected, until he eyes a girl named Kei Yonagi. Sometime after the audition, he gets into a debate with Stars Agency Ceo Arisa Hoshi about why Kei was rejected.
The following day Arisa's son Akira picks up Kei as a last-minute replacement to an auditioner who dropped out. This was at the request of Sumiji who took the opportunity to allow Kei a 2nd chance. He's seen to be impressed by Kei's method acting performance against a "feral dog", but in the end, she isn't picked.
Later that night, Sumiji arrives at Kei's home, tells her of his movie ambition, introduces himself, and asks her who she is.
- Sumiji enjoys drinking all types of alcohol. His favorite foods are rice crackers, oden, yakitori, gourmet delicacies, and anything that goes well with alcohol.
- He dislikes the high smoking rates in the movie industry.
- His hobby is secretly looking at the cute animal pictures that he saves on his phone.
- Unlike many of the other characters in the series, Sumiji does not like talking about his favorite movies or his film ideologies. He is the type of person who believes it is unsophisticated for artists to talk about their own work.