Hantsu x Trash

It's your standard romance ecchi series, but I like the swimming pool setting and the main characters. It flows quite well and I find myself rooting for the male character's final victory, which I find is a great indicator of the quality to the story.

The fanservice isn't too conflicting with the story and character progression. Rather, I like that the fanservice and ecchi is used to advance the story. This is usually what I look for in the ecchi genre, because life is full of ecchi, without being smut.

I like series like this one that can be mature (or rather appropriately immature) over those that capitalize and focus on the panty-shots or whatever.

I apologize for any grammatical errors that may appear, but English is not my language.

Unlike subtitled, "Sexy and Stupid Water Polo Comedy!!", manga is not just a fap material, and the story is not only about Water Polo. It can be said that the story is about the maturing of the protagonist (lazy, unmotivated and gave up everything quickly), which after entering the Water Polo Club and fall in love, begin to find their motivation.
The story is not very deep, but it's nice, and greatly improves after the appearance of Hayami character, enhancing the story and rhythm.

And yeah, the ecchi factor is a strong point!