Sword Art Online Extra Edition (2013)

During the pool party that the main characters have, they talk about how they met Kirito, and what happened in Aincrad (The Castle Sword Art Online took place in.) After one it cuts back to the pool, and Lisbeth grabs Suguah from behind to try and take her out of her floating ring, because she is trying to teach her to swim, but instead grabs her breasts, and starts squeezing and grabbing them, until Asuna eventually pulls her away. This lasts for almost 15 seconds.

Some of the girls wear revealing swimsuits during the party, and also when they go to the beach in-game.

There is a scene in a women's locker room and you see the girls in their underwear.

There're very revealing clothes some of the characters wear, however, they don't reveal any genitals.