Mizuta Mawaritosuki was the younger of the two Mizuta Twins, identical twin brothers of the Rumbar Pirates. He and his brother, Madaisuki, were identified by Oda in a SBS question. A fan asked why one of the Rumbar Pirates that died singing had a sword in his skull. Oda explained that this was because they were two identical pirates who died two separate ways.
Mawaritosuki wears polka-dot shirt with blue dots. He also has brown hair with a front part that is long, goes up, and hangs down. As an identical twin, he and Madaisuki share all of the same physical characteristics, except for differences in clothing. Mawaritosuki has less dots on his shirt than Madaisuki.
A long time ago, the Mizuta Twins joined the Rumbar Pirates. They, along with the rest of their crew, met Laboon, a young whale who got separated from the rest of his pod and followed the ship due to loneliness. The twins journeyed through the West Blue with their ship mates, fighting other pirates and singing music.
Eventually, the crew came upon Reverse Mountain, where they met Crocus. After staying at the crossing for three months and having fun, they decided to venture out into the Grand Line, leaving Laboon behind with Crocus.
After visiting a forested island, the captain, Yorki, became very ill. Mawaritosuki, with the rest of the crew, then witnessed their captain leave to prevent the disease from spreading.
At some point, the Rumbar Pirates engaged in a fierce battle with another pirate crew that left them devastated. Among the fallen was Mawaritosuki's brother, Madaisuki. The crew members who survived the fight were left poisoned by the enemy weapons. As a final hurrah, Mawaritosuki and his companions sang Binks' Sake a final time into a Tone Dial for Brook to give to Laboon after he is revived. Slowly, the crew succumbed to the poison, leaving all of the Rumbar Pirates dead.