Set in a small, unassuming diner in Shinjuku, Tokyo, that opens from midnight to seven in the morning, the series follows the enigmatic chef known only as the 'Master.' With a menu consisting solely of tonjorku (pork miso soup) and beer—though he is willing to cook anything his patrons request as long as he has the ingredients—the diner becomes a sanctuary for a diverse array of nocturnal souls. Regulars and newcomers alike share their life stories, heartbreaks, and joys over comforting, simple dishes, finding solace and connection in the quiet hours of the night.