|Affiliation||Kei Pirate Guild|
|Weapons||Poison needles, Tao Magic|
|First Manga appearance||N/A|
|First Anime appearance||"Creeping Evil"|
|English VA||Robert Martin Klein|
|Japanese VA||Akira Ishida|
Yase is an assassin member of the Kei Pirates. After Soi Len and Roi Fong failed in the attempt to steal the XGP 15A-II, Yase and several other pirates are sent to Sentinel III to ascertain their fate.
Yase, Kyokan and their group of pirates are informed of the location of Gene Starwind and the XGP 15A-II by Fred Luo. They arrived on Sentinel III to search for the whereabouts of Soi Len, Roi Fong and Hilda and reacquire the XGP 15A-II. After locating the Ehefrau in the wheat fields, he bugged the car so as to listen in on conversations between Jim Hawking and Gene Starwind, and presumably got the car impounded by the police.
With the help of the traffic controller, Yase planned to steal the Outlaw Star from Gene while Koykan attempted to capture Melfina at Starwind and Hawking. Yase's first attempt to breach the Outlaw Star was stopped by Gilliam II, who alerted Gene to the pirate's presence immediately. During his escape, Yase was caught in a gunfight with Gene who cornered him at the elevator of the docking bay.
He managed to escape, using his poison needles as an offensive measure. He was chased out onto a field by Starwind where he ambushed him with several foot soldiers. The next time he used his poison needles, he managed to wound Gene's side. After Gene went into hiding, Yase waited for Gene to bleed out; when he discovered what appeared to be the outlaw lying against a tree, he and the foot soldiers moved in to inspect the body. However, they discover the body of a dead foot soldier and are attacked with an explosive triggered by Gene's double-barreled gun.
However, Yase survives the explosion and attacks Gene when the outlaw lets his guard down. He demanded to know there whereabouts of the Hilda and the XGP. Gene refused to answer his questions long enough for the port authorities to arrive. Yase is forced to retreat, but not before declaring he would take back the XGP.
Once Yase realizes that Gene has succumbed to the affects of his poison needles, he attempts to ransom his health with the promise of an antidote if they surrendered the XGP to him. When they terminate communications with him, Yase is still allowed to as he pleases by the traffic controller. Using several mech suits, Yase and the foot soldiers attempt to force their way into the Outlaw Star.
Once Gene is healed by Melfina within the Navigation Tank, Yase and the pirates are forced to go on the defensive when the Outlaw Star's grappler arms successfully ward them off. Yase assumes he has the advantage when the grappler arms are unable to reach him, however, he confronted by Suzuka, who declares him a coward for hiding from his opponent.
Yase underestimates Suzuka and is not prepared for the destruction of his mech when her Bokken cuts the machine in half. He is forced to abandon the mech and pretends to surrender, begging for mercy. He attacks Suzuka when he assumes her guard is down, only for her to deflect his poison needles easily with her Bokken. Desperate, he attempts to attack her head on and is killed by a single blow from her Bokken.
Yase can be quite arrogant and confident in his abilities, in contrast to his fellow Kei Pirate Kyokan. Despite a tendency to boast and relish in the moment whenever he believes he has the upper hand in a situation, however, the Kei Pirate appears to prefer acting in indirect and often underhanded ways in order to achieve his objectives, both in and out of combat. In the face of superior opponents, Yase is quick to take cowardly and less-than-honorable measures in an attempt to subdue his foes and escape with his life. This is shown when he attempts to lower Suzuka's guard to begging for his life, only to try to poison her almost immediately afterwards.
In direct hand-to-hand combat, Yase excels at outmaneuvering his targets through speed, evasion, and diversion tactics. His signature attack are poisonous needles that he fires from bracelets on his wrists. Aside from the bracelets, Yase appears to know at least some basic Tao Magic, as seen when he uses a small shield to block an attack from Gene's gun.