Chronicles of Kartoba

A quiet life ends the night a young man's dormant vampiric blood wakes up, and with it comes a hidden world of ancient houses that all think his bloodline is already dead. Dark fantasy trappings, palace-intrigue stakes.

Dropped into that hidden society, he has to learn its pacts and hierarchy while hiding what he actually is, since being recognized too soon would get him killed rather than welcomed. Bonds get forged, truths get dug up, and his influence grows in the process, with his choices steering both his harem and whatever legacy he ends up rebuilding.

You play him: talk your way through the politics, decide who to trust and who to use, and push to reclaim a bloodline the world has already written off. The rest plays out through the usual visual novel choices rather than any separate combat or management system.