He Just Became the Adopted Son of the Richest Man, and Seven Fairy Sisters Want to Eat Him

There are monsters hidden in the urban background. The protagonist is a human with a "Tang Monk Flesh" physique, who is adopted by the Queen of the Monster Race (whose external identity is the chairman of a multinational conglomerate). Identity changes: Ordinary human -> Prince of the demon clan. Sister group: Eldest sister Nine-tailed Fox (Queen of Movies), second sister Cat Demon (Internet celebrity), third sister Dragon Girl (Overlord of the Deep Sea)... Escalation of conflict: The enemy is a demon slayer and a wild monster that wants to eat the protagonist. The sisters drooled and wanted to eat the protagonist, while frantically protecting him from being eaten by outsiders. Goldfinger: "The Lord of Demons System". Not only will you not die if you are "sucked" (intimate contact) by your sisters, but you will gain demonic power and evolve into the strongest half-demon.