He worked with his twin brother Gōzu,his was atchuunin-level and was apart of the village Hidden by Mist before becoming mercenaries alongside Zabuza and Haku.
In the beginning of the series Zabuza sends the demon brothers to kill Tazuna. Using their 'Hiding in Water Technique' they surprised Team Kakashi. Gōzu immediately hurling his brother in front of him, then pair have a chance to kill Kakashi. As they move on to attack Naruto Uzumaki, but they come to a stand still when Sasuke Uchiha breaks the chain connecting the two brothers. The brothers separate and attack the team. using the body replacement technique Kakashi escaped their first attack, then takes them down. He later ties them to a tree so that they can be taken into the Konoha custody.
Meizu has completed 278 official missions in total: 68 D-rank, 167 C-rank, 43 B-rank, 0 A-rank, 0 S-rank. (According to the Naruto Official Data book)