Keiko Nogiwa holds the position of Deputy Captain aboard the Kii, a student-operated Yamato-class training battleship from the Sasebo all-girls marine school. The vessel serves as the flagship for Sasebo in an inter-school competition hosted in Yokosuka. At the time of the Totalitarian Disease incident, the Kii was on a distant voyage across the globe, preventing it from aiding in the effort to halt the infected Musashi. It returned to Japanese waters in time for the Yokosuka competition. There, the Kii joined a combined student task force on a mission to intercept a pirate-controlled mobile sea fortress before it could enter Tokyo Bay. During the assault, the Kii delivered supporting fire against the fortress. Keiko Nogiwa performs her duties under the command of the Kii's captain, Sachiho Chiba.