A bored Rimuru Tempest accompanies Diablo when he goes to meet with an old friend in the Netherworld. What will happen when he meets an out-of-place human boy who piques his interest? (Tensei Shitara Slime Datta Ken and Mairimashita Iruma-kun crossover)

It has been 12 years after the Great Tenma war. Rimuru is ever-busy with the reconstruction of his capital, the treatises between nations, and his harem. On a date with one of his subordinates, a mysterious magic circle forms beneath them, and they get summoned to another world. Only to find out, he was summoned completely by accident! What will be his fate, or rather, the fate of the world he finds himself in? I do not own any of the characters. All characters portrayed are owned by their rightful owners. Image by foxhall There are some pretty big spoilers in chapter 2 for Tensei Slime, so if you wish to skip it, feel free to. It's primarily an explanation for Rimuru's current relationships. (A/N: If you're reading this, it means that I re-formatted the first two chapters and edited the second one a bit to add a little more content and fix some grammatical mistakes.)