Sukeji Yabu serves as a Petty Officer 1st Class in the engineering division aboard the Space Battleship Yamato, hailing from Mie Prefecture. He is Chief Engineer Hikozaemon Tokugawa's favored student, having previously worked under him on the battleship Kirishima. Yabu possesses first-class engineering skills but exhibits a skeptical and timid personality, frequently expressing doubts about the Yamato's missions and their chances of success.

In the original continuity, Yabu's skepticism culminates in him leading a mutiny during the voyage to Iscandar. Convinced the mission will fail, he and nine others aim to establish a colony on Iscandar, kidnapping crew member Yuki Mori as their designated "Eve." They flee to a crystal island, where Yabu and the mutineers perish in a tsunami and volcanic eruption; Yuki Mori survives.

Within the remake continuity (*Yamato 2199*, *2202*, *2205*), Yabu's role transforms significantly. After the events of *Yamato 2202*, he becomes a cross-cultural technology ambassador, facilitating engineering knowledge exchange between Earth and Garmillas. He maintains his engineering position under Tokugawa on the Yamato and operates the AU-09 Analyzer unit. This autonomous robotic system, equipped with advanced artificial intelligence for independent thought and action, functions as a general-purpose analysis terminal. It prefers the name "Analyzer" over its unit designation. Yabu voices the Analyzer unit alongside his engineering responsibilities.