Known as the Nero the Sea Weasel, Nero was considered the newest member of CP9. He was first introduced on the Puffing Tom, where he was helping to escort Nico Robin to Enies Lobby. However, as Nero is still a new recruit, he is only a yonshiki-tsukai (四式使い, four-power user), instead of a rokushiki-tsukai (六式使い, six-power user). The rokushiki that Nero has mastered are soru, geppou, kami-e, and rankyaku. He is still unable to use tekkai and shigan. However, he compensates for his lack of shigan by carrying guns with him, and compensates for his lack of tekkai by being very careful to avoid taking blows.

Nero attempted to stop Franky from rescuing Robin but was punched through the roof of Puffing Tom, into the room where the rest of CP9 was. Nero then continued to try to fight Franky and stated he would kill him, but Lucci wouldn't allow this, as they were simply supposed to be capturing him. Lucci then gave Nero three seconds to escape, at which point Lucci quickly took him out with five shigan attacks. Lucci then personally disbanded him from CP9. It is unknown whether or not Nero is dead or alive, as Lucci is a very skilled, shoot-to-kill sort of person, and Nero's limp body was thrown into the ocean during Aqua Laguna, one of the biggest storms in the world.