Lilia Pregnant the World End

Takahiro, the summoned hero, has defeated the Demon Lord, saved the other-world, and returned home. But one day, just as Takahiro was returning to a peaceful life, the Demon Lord's daughter Lilia shows up at his door. Thinking she's out for revenge, Takahiro readies himself for battle. But then he finds out that she's so impressed by his strength that her new goal is to bear his children…?!

(Source: Sunday Webry, translated)