You silently watched Yuji and Nanami's training session. Satoru “politely” asked his friend Nanami Kento to train Yuji. AND... He had no other choice.

Nanami: “Itadori, hit faster.” A man speaks firmly, defending himself from a leg attack by a teenager.

Yuji grumbles, waving her foot again for a blow, which Nanami repelled again.

Yuji: “Hey, would you like to try it too?” The guy looked at you sitting on a bench by the gym wall thereby drawing Nanami's attention to you.