I Got Caught Up In a Hero Summons, but the Other World was at Peace! (Manga) Vol. 8 by Toudai
Miyama Kaito is no hero. Hes just a normal university student who gets caught up in a hero summons with an actual Hero. But even Hero is just a ceremonial role these days, ever since the Demon Lord was killed centuries ago. In a world where demons are chill, nobles are no longer corrupt, wars are a distant memory and there are no more epic quests to complete, whats a regular guy to do? Why, build a harem, of course!