Who needs hygiene you could invite a maid over, am I right guys

there is a bath house across the street... and an adorable goddess of a maid to help you clean up... so he's got options

Well the size of a bathroom can be deceiving however as a shop I doubt it has a shower installed so the places most likely he may take a shower is in the bath house or at school. maybe after futaba joins the team he is able to take showers at Sojiro's place.

He always tries to go shower, but "Let's not do that today."

There's a bathroom in LeBlanc and he bathes in the sink.

Pfft, you all aren't actually thinking this through hard enough. Obviously he goes online and buys gamer girl bathwater, then immediately pours it on him when it gets shipped to his location.

He does carry millions of yen on him at all times... That actually makes a lot of sense...