“The Mature Idol Project” - The latest project proposed by Manpuku Entertainment Productions, in a bid to revive the company. Experienced in the successes and failures of the business world, 6 middle-aged men now face the many hurdles of age and physical ability, whilst pursuing their goal to become idols. In an effort to prove that old dogs can learn new tricks, and that you can still learn to shine no matter your age, these middle-aged men, at the end of their ropes, are taking a stand!

High school Kaito gains a card that summons a warrior maiden after defeating a rare slime. He admires his popular childhood friend but this discovery gives him a chance for an extraordinary life, battling in a modern fantasy world.