Shigeru was one of the Yakuzas that was with Kienji when he was assassinated.

Sift Heads 4

Shigeru appears (without being named) for the first time in Sift Heads 4, mission: Shadow of the Traditions. 

Sift Renegade 3

 Shigeru appears only in two missions: "The Grand Hotel" where he is probably just knocked out by Kiro, and "The Case Kienji" along with Shawn and Kienji. 

Sift Renegade 3 Defiance

 After Kienji found that Yuuma was betraying the clan tried to go on the mission where Kiro should be, but only found Shigeru, who said Kiro was on another mission and that would take him to Kiro. On the way Hayate found tied to a chair, but it was a trap. They found Shawn after escaping. Shigeru and Shawn were with Kienji when he was assassinated.    

Sift Heads - Street Wars Prologue

 Shigeru appears in the Sift Heads - Street Wars Prologue. Shigeru this time is completely different, he now has a scar on his eye and a snake tattoo on his body. Shigeru was right-hand-man of Gen but after of his death Shigeru became new leader and new greatest grandmaster of Yakuzas and Jackson as one of his co-leaders and one of grandmasters after death of Gen. Shigeru was only appeared in introcutscene of Sift Heads Street Wars. 

Sift Heads - Cartels Act 3

 Shigeru appears again in Sift Heads - Cartels Act 3, its appearance is the same as it was in Sift Heads - Street Wars Prologue.Shigeru tries to break into Vinnie's house through the window, but Vinnie receives a message (by computer) that someone was breaking into the house. Quickly, Vinnie dodges an attack at Shigeru and the two begin to fight. Shigeru and Vinnie end up falling out the window.The two end up falling on a roof, then Shigeru tries to kick Vinnie, but Vinnie is faster and grabs his leg and the two fall together.Shigeru ends with an iron bar across his body. Jackson helps Shigeru and tries to kill Vinnie,but Kiro arrives and shoots their car, and Jackson flees with Shigeru.Kiro chases the Yakuza, throwing them in the car but is out of bullets. Vinnie then arrives and crashes his car in the Yakuza. Jackson is died and corpse of Jackson was in car but Shigeru then flee into the HQ of the Yakuza.Vinnie manages to kill Shigeru and escape out of the Yakuza HQ alive,but he gets arrested by the police.