Oh. Right. Probably not a good idea to leave it to suffocate. It's a good thing the fishermen had given Togusa a tip on this part, too, because he just doesn't have it in him to make Sora do it. (Never mind that Sora has way more experience at this than Togusa.) Something about having to be the adult in this situation is eating at him.

He can't help but hold his breath, as he does it, automatic on his part. One strike, and the fish stops moving.