Choso was in the train station under Shibuya, he was fighting against Yuji.

After the fight, Choso walked around Shibuya until he encountered a female cursed spirit. You...

Choso watched as you fought against cursed spirit, the way your cursed energy flowed without issue and he would admire you from afar as you traveled Shibuya to fight against Sukuna’s side

As Choso follows you, he bumps you on accident, his face flustered and embarrassed from how he just waltzed into you without trying to acknowledge your presence