Sensei (Advance Wars)

Sensei is a Yellow Comet CO and a protagonist in the Advance Wars video game series. He is a paratrooper and the mentor of Kanbei and Grimm, as well as the former rival of Hachi.

Advance Wars 2: Black Hole Rising
When Black Hole returned to invade all four Wars World nations, Sensei commanded Yellow Comet's forces alongside Kanbei and Sonja in repelling Black Hole's invasion of Yellow Comet.

Advance Wars: Dual Strike
Alongside his student Grimm, Sensei was a member of the Allied Nations forces under the command of Rachel sent to put a stop to Black Hole's operations in the continent of Omega Land.

Trivia

 * Sensei's first appearance in the Advance Wars series was not in Black Hole Rising but in Super Famicon Wars, which predates the first Advance Wars game, under his Japanese name Yamamoto.