須々岐水神社, Shinto shrine in Japan

Susuki Mizu Jinja shrine, also known as Haku-gu Taisha, is a small Shinto sanctuary in Matsumoto located about two kilometers east of Matsumoto Castle near the Haku-gawa river. Simple buildings with thatched roofs and wooden walls surround shrine grounds that feature old stone statues and nine stored festival boats standing about five meters tall.

The shrine appears in the Nihon Kōki in 799, when a man of Goguryeo descent named Ke Shinshi was granted the surname Susuki. In 867 the Nihon Sandai Jitsuroku records its promotion from Senior Sixth Rank to Junior Fifth Rank. A wooden komainu with an ink inscription of 1458 survives, and ridge tags from 1680 onward remain in the main hall.

The shrine's name appears in the Nihon Kōki for 799, when a man of Goguryeo descent named Ke Shinshi was granted the surname Susuki. The annual Ofune Matsuri, held every 5 May since the Edo period, brings nine neighbourhood associations together to haul their festival floats, called ofune rather than dashi here, into the shrine grounds. All nine carved floats are designated Nagano Prefecture Treasures.

The shrine is about twenty minutes by taxi from Matsumoto Station or approximately seven kilometers by car from the city center. There is no parking available on site, so arriving by bus or taxi is recommended with a short walk to reach the sanctuary.

The nine festival boats, called "ofune" rather than dashi, belong to nine neighbourhood associations and are each carved and designated a Nagano Prefecture Treasure. They are hauled to the shrine grounds for the May 5 boat festival, held since the Edo period. The shrine also keeps a wooden komainu pair bearing an ink inscription dated 1458.