FALLBACK ROOM

On the day he turned twenty, Patrick received word that he was to return as the family's official heir. He returned to the mansion with a fluttering heart, but the house was eerily quiet. One night, exhausted and asleep, Patrick was awakened by someone's kiss... Before his eyes stood Ebel Moltun, the picture of a perfect gentleman. “Patrick, have you been well?” Despite the affectionate tone, Patrick soon finds himself imprisoned by this unknown man...(Source: MrBlue, translated) — Description from AniList community (anilist.co).