Jin is a sloppy man who couldn't care less about his own appearance. He dislikes exercising. His job is to monitor the students' health, but he completely fails at taking care of himself. He's a physical therapist and is in charge of general education.
He often shuts himself in the infirmary, which has become the base and center of his life, and reads books there. Due to his friendly manner of speaking, he's well-loved by the students. He used to be a celebrity in the past. He met the teacher Akiomi Kunugi during that time, and they've been acquaintances ever since. They share friendly chats every now and then.
- Broken Pedestal:
- Akiomi used to admire him during the April Fools content but he can no longer see Jin as the man he once was now that he changed.
- He was also this to Sazanami Jun's father who had asked Sagami to fulfill the former's promise to keep being an idol. So after he retired to become a doctor, the man outright called him a liar and the hatred extended that Jun himself didn't like Jin at all.
- Beauty Mark: Below his right eye, which, curiously, is in the same spot that Yuzuru's is.
- Shellshocked Veteran: The April fools content revealed that he originally wanted to be an idol for a sickly girl he had a crush on, but sadly, said girl passed away from her illness. It seems to have become a sour point for him that he left the entertainment world and become a doctor instead.
- Wholesome Crossdresser: Apparently cross-dressed for a period in the past, according to Test of Courage gacha.
Fast-paced, serious, and high-strung, Akiomi is harsh on both himself and others. He's in charge of the idols' specialized curriculum and student guidance, and he also acts as the advisor of the Student Council. He's courteous and polite, but has a sarcastic manner of speaking. He can't help but give cautionary warnings to students who concern him, no matter how slight the reason may be.
He used to be a multi-talented idol who started his career in modeling, but has since resigned and become a teacher instead. He's known the school doctor Jin Sagami since his days in the entertainment world.
- Hard Work Hardly Works: Somewhat zigzagged. The April Fools event shows that he put in a lot of effort in becoming a great idol, which did in fact work, as he became a distinguished idol as a result. But the entertainment industry only used him to make Jin the "super idol" look better, and if Jin didn't do anything, he would have been "destroyed" as an idol regardless of the effort he put in.
- Stoic Spectacles: He always appear to be very grumpy looking and rarely smiles. Unlike Keito, however, he can still smile, as hinted in the Test of Courage gacha and if the players choose the correct answer when they encounter him by pressing onto an empty lesson area.
- Voiced by: Shin-ichiro Miki
A Former Idol who happens to be Hokuto's father.
- Doting Parent: Despite neglecting Hokuto, his character and official description paints him as very affectionate towards his family, and cards that feature him show him trying (and failing) to dote on his son. One of his Likes is photos of Hokuto, for crying out loud.
- Strong Family Resemblance: He's practically a taller version of Hokuto with a different haircut.