It's common knowledge that pink-haired beauties are generally gentle, kind, considerate, and virtuous—ideal girlfriends and wives. Watanabe Yuuki, transported to another world, is surrounded by such beauties: his childhood friend is pink-haired, his neighbor is pink-haired, his school seatmate is pink-haired, the girl in the next class who likes him is pink-haired, his teacher is pink-haired, the stalker girl who's been following him is pink-haired, the beautiful girl he meets is pink-haired, and even the alien is pink-haired. Pink-haired is fine; they're all cute, and he likes pink-haired girls, so finding a girlfriend and living a happy life shouldn't be difficult. But his childhood friend went to study in England, his neighbor is a socially awkward seamstress who stays home all day, and his seatmate is also socially awkward and plays in a band. For some reason, the stalker girl who's been following him is out of the question. He can't betray his ancestors, can he? The beautiful girl he meets seems to have some mental issues. The alien is another story—what about being raped? All the pink-haired girls around him seem a bit off. Why is finding a girlfriend so difficult? So, Watanabe Yuuki turned his attention to Goto Jiri, the most normal-looking among the group of pink-haired girls. Goto Jiri: Yuuki-onii-chan, I'm only seven years old this year.

"From this moment forward, you are the commander of the Five Carts Academy and the Anti-Demon Ninjas. The task of fighting against the demons will be entrusted to you." "Eh? Wait, wait, wait! Are you sure? I'm not even an Anti-Demon Ninja!" Omega was thus entrusted with this important task in a daze. If the task of being a commander was merely to fight against demons, it wouldn't be a problem. But the challenge also included these humanoid self-propelled juicers who could easily 'suck the floor'. At that time, Omega wouldn't even be able to protect his own underwear, and it would be a success if he didn't get squeezed into a mummy on the spot. And whether Omega's final fate is to become a water dispenser that never runs dry, or the Anti-Demon Ninjas to become one after another, one after another, firearms, this prelude has already begun, and it seems that no one can stop it.