>>1642731You'll have to progress further in the game.
As you clear stages you'll find that instead of getting a game over screen on defeat, you'll get captured and stripped. You'll then be in a minigame of sorts where you control the generic enemies (you unlock more as you progress). Eventually, there will be a pink exit option at the bottom of the list. You'll see Momoka run out without any clothes on, and you'll start the stage shown in the image I uploaded above. (The stage is actually pretty hard.)
There's also a hot springs stage where you have to fight off a large mob of enemies. There are some blue hooded enemies that will dive bomb you and if they hit you, they'll steal your towel. There's a small bonus CG for keeping your towel on, but it's just her doing a jump kick with her towel on. This stage is repeatable and can be done pretty early on.
And, once you beat the game there will be four (frustrating as hell) bonus stages. When you start, you can choose to start the stage in any costume (normal, swimsuit, karate gi, bath towel, and a hidden naked option).
>>1642716I think I'll change my vote to A, then. After reading
>>1642713.