In Episode 1, a boy strips his clothes and says I'm just going to skinny dip and jumps in the pool all that is shown is the boy's buttocks

The anime revolves around a swim club, so many muscled shirtless men are seen.

A character is sometimes seen in the bath but we don't see any nudity.

A young man sees another young man's muscled chest, gets flustered and shouts "cleavage!".

In an OVA episode, young men wear maid dresses and one other guy pulls up their dresses to reveal underwear.

Some characters get into fights and arguments and throw punches, but no blood or gore is ever seen.

A character pushes another character against a fence and various walls. The same young man presses a different guy up against a tree. These scenes could be seen as mildly aggressive.

Some uses of "bastard", "crap", "bitch", "hell", "damn", "screwed" and one use of "shit". Some episodes have little to no profanity.

None.

One character has a phobia of the ocean. He swims out into a violently stormy sea to try and save his drowning friend, but has flashbacks to a time when someone close to him drowned, and this could be upsetting to some viewers.

Young men sometimes have heated arguments, and these can get really quite sad and emotional at times.