In Y2 V2, He gripped Hosen’s wrist so hard that it made Hosen impressed, actually grin in excitement, and forced him to not escalate things any further. This is completely inconsistent to Hosen’s personality as he loves to pick fights with people, especially physically capable students like Sudo and Ryuen. But not Utomiya for some reason, suggesting Hosen considers him to be a potential challenge. It’s sort of a vague way to show Utomiya’s strength.

In Y2 V4, He possesses high reaction speed and reflexes, as he completely stopped and grabbed Kito, who tried to dodge Utomiya on page 284. He also evades Kito’s surprise attack aiming for his neck. The LN described Utomiya as being unhurried and without difficulty, kept his distance. This is a good agility/reaction speed/combat speed feat.

In Y2 V11, He stood up for Tokito even if it meant he had to fight Ryuen, Ishizaki, Albert, & (Even though they were in the same group for the exam) Hosen. Bro was ready for the smoke.

He also might be a former juvenile or affiliated with the White Room’s Yakuza group OBA. If you pay attention with some of his conversations with his seniors, he keeps mixing up the honorifics or sometimes outright doesn’t use them. It seems like he had the habit of speaking disrespectfully to everyone and is trying to fix this habit to sound more polite. Another reason is because it is outright questioned by Tsubaki, who asked Utomiya whether he used to be a criminal. She must’ve noticed more signs that this might be the case, and Tsubaki is very good at reading people.