| Length: | 0.0135km (00.0084miles) |
| Mouth: | Koshira River |
| Mouth Coordinates: | 33.5721°N 135.916°W |
| Subdivision Name1: | Japan |
| Subdivision Type1: | Country |
| Width Avg: | 1m (03feet) |
| Subdivision Type2: | Prefecture |
| Subdivision Name2: | Wakayama |
| Subdivision Type3: | Town |
| Subdivision Name3: | Nachikatsuura |
The Butsubutsu River is a second-class river that flows through the Konoshiro district of Nachikatsuura Town, Higashimuro District, Wakayama Prefecture . The total length is 13.5 meters (also: 44 ft) and the river width is around 1 meter. With the designation of a second-class river in 2008, it became the shortest river in Japan under the River Law.
The rivers known to be short before that were the Honbetsu River, which is the same second-class river and flows through Shimamaki Village, Shimamaki County, Hokkaido, and the Shiono River, which is a quasi-river with a total length of 15 m and flows through Mamurogawa Town, Yamagata Prefecture.
It is a tributary that flows into the Koshira River, and its water source is spring water. In "Shimosato Village Magazine" (1918) before the merger, it was written that the spring springs from the bottom of the river, which is commonly referred to as "butsubutsu", and it is said that the name comes from the appearance of bubbles popping out. .. Residents in the area still use it to wash drinking water and food, and when the water was cut off due to flooding in 2011, people who asked for drinking water lined up.