This was pretty fun and I like what you've got here so far. The characters are fun and the plot is interesting so far.
As others have said the biggest problem is the balance, not even necessarily the difficulty. The 5 starter outfits were absolutely not created equal. Since the combat is mostly focused around elemental combos your turns will either be spent casting the water spell or using items. So the maid outfit giving you +ATK kinda goes to waste. I get that this is sort of the point but I wish picking it also gave you a way to spread water marks with a physical attack, like a TP skill that dumps dirty laundry water on an enemy.
Cowgirl +def and goth loli +mag are definitely more useful than the rest.
I really like how the 5 outfits relate to your 5 party members(goth loli for the chuuni mage, sundress for the rogue regular girl, maid for the aristocrat duelist, cowgirl for the farmboy, and lewd dress for the rapist knight). But if that initial outfit choice locks you into their route then it might be frustrating.
Would letting you swap outfits every time you pick a new piece of clothing be possible or would it lead to too mqny branches?