Aichō, known as Aichō of the Sky or Rooster Ninja Aichō, formerly commanded the 10th Division Ninku Unit. A childhood marked by neglect forged an intense hatred for humans, shaping his hostile worldview and early interactions.

After the Empire defeated and disbanded the Ninku corps, Aichō reunited with fellow captains Fuusuke and Touji. Despite his ingrained animosity, he forged a strong, loyal friendship with them. His personality varies between media: the manga depicts seething contempt for humanity, especially directed at Rihoko until discovering she is Touji's sister, which softens his stance. The anime adaptation shifts this trait into comical misogyny, with frequent insults aimed at Rihoko due to her persistent romantic pursuit.

Aichō specializes in powerful sky-based techniques, utilizing his exceptionally strong legs for devastating aerial assaults, high-impact combat, and mobility, often targeting enemy machinery. His appearance evolves: flashbacks show short black hair with reddish-brown dye, while later events in the Second Stage reveal blonde hair. His signature attire is blue denim jeans, a black tank top, and brown shoes.

In the OVA "Knife no Bohyou," set after the war, Aichō spearheads a mission to deliver a memento to Makoto, the sister of a fallen comrade, and aids in defending her village against pirates. This story reinforces his core traits—formidable combat skill, deep distrust of outsiders, and unwavering loyalty to his Ninku allies—without introducing new development or background. Aichō's journey traces a path from isolation to camaraderie, yet his foundational cynicism endures across all official media.