Sketch by an eyewitness
Japanese manga artist and television personality Yoshikazu Ebisu reported on his brother's experience seeing strange creatures on a 2009 TV show.
Nagasaki Marine Reptile[]
Yoshikazu's older brother Kosuke was 17 years old in 1958 when he was fishing in the waters of Nagasaki Prefecture when he pulled up the carcass of a strange creature. This is 3 to 4 meters (10 to 14 feet) long, with a thorny fin on the front half of its back, limbs with fingers, and fangs protruding from its mouth. Kosuke described the carcass as dinosaur-like. This carcass was so decomposed and had such an offensive odor that Kosuke dumped it into the ocean.
Saohana Case[]
Other sightings occurred around 1930-1960. At a place called Saohana in the Goto Islands of Nagasaki Prefecture, a fisherman went out to sea at night on his boat and was contacted by another fishing boat asking for help. There was a huge crocodile-like creature in the water near the fishing boat, and it was targeting the crew from the sea. One of the fishermen who came to the rescue made a harpoon from a bamboo stick and a knife, and repelled the creature by piercing its mouth.
Source[]
https://cryptidz.fandom.com/wiki/Nagasaki_Marine_Reptile
https://cryptid.blog.jp/archives/6650464.html https://cryptid.blog.jp/archives/6920124.html