Season 1 of Unforgotten Night premiered on June 22, 2022.

Kim, a 25 year old office worker, has long held unrequited feelings for his beloved senior, Day. In a genuine attempt to forget about Day and move on with his life, Kim decides to give into his inner lust and pursue a one night stand with a random stranger he meets at a bar. But little does Kim know that this stranger is bound to fall for him irreversibly, to the point of no return.

Meanwhile, Kamol, a 36 year old mafia, is a man with special needs in bed who actively switches partners as no one is able to satisfy his desires in its entirety. By a curious twist of fate, Kamol crosses paths with Kim at a bar one night and the two then decide to engage themselves in pure carnal pleasure thereby making Kamol realize that he's finally found the one who's able to perfectly fit his needs. At this point, Kamol decides to make Kim his own and starts pursuing him irrevocably.