Blueno

Personality
While the entire Water 7 CP9 unit gives the first expression of emotionless justice-devoted killing machines, Blueno is the only one to maintain such a façade. While the others- Kaku, Lucci, Kalifa and Jyabura- are shown taking pleasure in fighting, toying with their opponents and so on, Blueno remains calm and collected nearly all the time. As a result, Blueno comes to symbolize the cynical, evil actions of the world government - namely using Nico Robin, blackmailing her through traumas inflicted by the World Government in the first place.

Powers and Abilities
Blueno ate the Doa Doa no Mi (ドアドアの実 Door Door Fruit) which allows him to create doors on any surface. He has even created "air doors", doors in the air itself, which lead to what seems to be another dimension. Blueno is also able to create doors on people, and did so to Luffy's face, causing it to spin like a revolving door. In battle, Blueno also uses his door to move freely through the entire environment, setting himself up for sneak attacks, and even creating small doors wherein he traps his opponents' feet.

Blueno's tekkai seems to be the one of the more powerful ones of the group, and he was the first to reveal any variations of the move. However, despite this advantage, Luffy was able to use his new Gear 2 abilities to defeat him when they fought in Enies Lobby. Lucci stated that Blueno's bartending job has dulled his senses, but it might just be another show of the arrogance of most of the CP9 unit. Nevertheless, with Luffy only having recently developed his Gear Second mode around the time when he used it against Blueno for the first time in combat, Blueno has been made memorable as the first adversary to receive the honor of witnessing Gear Second's first activation, as well as the first to be subsequently felled by Luffy while in this state.

History
When we first meet him, he is seen as a bartender in Water 7 and seems to be the most friendly with Franky and Paulie, talking with them about life and their current activites.

He soon shows his true nature when he, along with the rest of CP9, attacks Paulie and Iceburg for the Pluton blueprints. He is the agent that Robin ran into on the streets in Water 7 while she was with Chopper, as well as the agent whose Devil Fruit powers were used in both attempted assassinations of Iceburg. His power was also vital in thwarting Sanji, Franky and Usopp's attempt to rescue Nico Robin on the Sea Trains.

However during the debriefing when the SH invade Enies Lobby, he notices Spandam's phone off the hook and realizes something amiss. His instincts prove right as he meets Luffy on the roof of the Courthouse of Justice and fights against him. Unlike their last encounter on Water 7, Luffy manages to break through his Tekkai as well as figure out the "soru" move to fight him evenly. Not only that, Luffy reveals his new Gear 2 technique to him, literally pounding the CP9 agent around the roof. After a bit more fighting Luffy goes to finish him a Jet Bazooka, rather then dodge Blueno decide to take it head on with his strongest Tekkai which he manages to stay on his feet after the impact. Luffy then goes to show his Gear 3rd technique to him but Blueno collapses shortly there after, having been knocked out from the Gear 2nd move before in something of a delayed reaction.

After the Buster Call left Enies Lobby in ruins, Blueno turned out to be the savior of CP9, using his Air Door to protect them from the annihilation of the island by the Marine onslaught. He and Jyabura were the first to overhear Spandam's plans to capture them as scapegoats to blame for the failure of their mission, and later is seen walking along the Sea Train tracks with the others. They have now all reached St. Poplar and are assisting Jyabura by collecting money for his act. He is later seen at a café with Fukurou, Kaku, and Jyabura waiting for Kalifa and Kumadori to return with the shopping, reading what appears to be a newspaper as the others have a drink. After Lucci was discharged from the hospital, He and the rest of CP9 went for a bowling match. However, when police appeared, Blueno became paranoid that the World Government was coming for them due to them being possible fugitives. But it turned out to be the Candy Pirates invading the town, so he and CP9 dealt with the pirate problem. In Chapter 511, Blueno is seen flykicking one of the pirates on the ship.

Trivia

 * In the Volume 44 SBS, it was revealed that when Blueno was younger, he loved baseball.
 * He has a bull theme, due to his horn-like hairstyle. He is also referred to as a cow by Luffy numerous times.
 * When invading the Iceburg's mansion he was wearing the bear mask.
 * In a recent Weekly Shonen Jump poll to determine the most popular One Piece characters, Blueno ranked at 81st.