In a world where one's entire life is determined by contracts with magical beasts, Zeke, a pauper who formed a contract with the weakest of them all - a Slime - lived a life filled with regret and scorn from those around him. He eventually grew old and met a despairing end... or so he thought, until he found himself regressed to his childhood! Determined to give [Fios] - the only partner he truly connected with in his previous life - a better fate this time, Zeke resolves to turn his life around. Aiming to rise from a slum cleaner to the head of a grand merchant association, he sets his sights on the slime's ability to dissolve anything. What's more, it seems his slime partner also possesses a hidden power...?