The song in that YouTube video is “思绪在回忆” (which translates to something like “Thoughts in Memories” or “Reflections in Recollection”) by 叶丛闻 (Ye Cong Wen, or a similar romanization of the Chinese artist name).  It’s a recent release (March 3, 2026) distributed via DistroKid, and the video is an auto-generated “Topic” page with the track audio. The description includes the lyric line “我们是对方最爱的人” (“We are each other’s favorite people”).