I've Become The Demon King, For Real?

Gender Bender Action Adventure Comedy Fantasy School Life

After a terminally ill boy closes his eyes, he awakens once more to find himself transported to another world — and not just as anyone, but as the lofty Demon King himself. He successfully inherits supreme power capable of standing against the entire world. Yet there are always fools who overestimate themselves and dare challenge the Demon King’s might. “When I had just transmigrated and didn’t know anything, I let it slide. But now… what should you call me?”