The Hahagawa is a 7.5km stretch of river that flows through the Kaifu region in Kaiyo. It runs mostly parallel to the larger Kaifu River, eventually merging with it at the end of its stream.

The river is home to multiple attractions, most notably the Genji fireflies, which we celebrate with a week-long festival in early June each year. The firefly festival is so popular, it draws many tourists from all over Tokushima prefecture. During the festival, locals run festival stands along the riverbank in the evening, but the main attraction is the nightly boat ride.

For the most up to date information about the firefly festival, check out the town’s tourism website.

The Hahagawa river is also the natural habitat for a protected species of giant eels, which can grow up to approximately 2 meters in length and weigh up to 20 kilograms. There is also peculiar split rock formation found in the river, which is the subject of a legend involving the giant eels (translation provided below).

More information about the rock can be found on the town’s tourism website.

Following the river upstream will eventually lead to the Namikiri Fudoson temple.

The river can be accessed via car. It can also be reached via a 20-minute stroll from the Kaifu Station.

For those interested in a complete English translation of the giant eel legend, and the historical explanation sign located near the river, please take a look below!

A long time ago, there was a great eel that lived in the Hahagawa river that hid in the crevices of a large rock. The great eel eventually grew to the point where it could no longer get out.

Because the great eel was unable to leave the crevice, baby eels worked hard to bring in food to feed the great eel. However, the great eel’s body kept growing bigger and bigger until one day, it finally split the big rock in half.

The rock has since been called 'Seriwari-iwa' or 'Sake-iwa', and has become a habitat for giant eels.