Five heroes were summoned to defeat the Demon Lord! However, the power given to the protagonist, Hojou Fuyuy, is an 'Infinite Bathroom'? Can he fight with this? Who is the idiot who says he can defeat the Demon Lord with this power?! But someone once said, "It depends on how you use it." Can he really fight with this? A mixed bath fantasy of swords, magic, bubbles, and skin! Save the world by taking a bath!