It was originally serialized in the newspaper Yomiuri Shimbun between July 25, 2006 and April 23, 2007, before being released in bound format by publisher Chuokoron-Shinsha exactly one year after its periodical debut.

The story takes place in modern Japan, and centers on a group of three rats, a father and two young sons, who must find their way back to their river home after being displaced by human construction workers.

A family of three rats, brothers Tata and Chichi, and their father, referred to only as "Dad", live in a tree trunk beside a river just outside Tokyo, just as their ancestors had for generations.

Time becomes a factor as winter is fast approaching, leading the trio to venture in and around the dangerous city, encountering allies and enemies of all shapes and sizes.

[2] The special was directed by Tetsuo Hirakawa, and features animation by Studio Gallop,[3] as well as the theme song "I'm Here With You" written and performed by Yusa Mimori.