Naka Makoto owns a small ramen restaurant called Naka, where he serves a loyal clientele, including his partner, Tomatsu Shimpei. Naka-san no Nagare focuses on the lives of Naka-san and Shimpei, especially their mutual love of ramen.

The volume also contains a series of shorts about two employees of an art supply store in the same neighborhood as Naka-san's restaurant.