People in the city of Takamatsu in Kagawa Prefecture, western Japan, braved freezing waters to take part in a first-swim-of-the-year event featuring a traditional swimming style known as suininryu.

The aquatic custom dates to the Edo period between the 17th and 19th centuries. A local lord promoted the swimming style as a form of martial art. It is designated as an intangible cultural asset of the city.

Thirty people joined in the annual event on Tuesday, which was organized by a local group that works to preserve the tradition.

The swimsuit-clad participants slowly immersed themselves into the sea, which was a chilly 8.5 degrees Celsius.

While treading water, one member of the group used a brush to write on paper the kanji character for "rabbit," which is this year's Chinese zodiac symbol.

The participants then performed the traditional method of swimming to the beat of Japanese drums.

A 73-year-old man said he has taken part in the event 34 times. He said he prayed for health and peace this year while swimming.