At the onset of the One Year War in UC 0079, Kai Shiden was living in the space colony Green Oasis in Bunch 1 of Side 7. Kai Shiden is tall and lanky in stature with a mop of gray hair, and his snarky and sarcastic personality often gets him scolded or slapped. After surviving the Zeon attack on Side 7, Kai became one of the many evacuees escaping on the Pegasus class assault carrier "SCV-70 White Base". However, due to a shortage of crew and soldiers to staff the warship, Kai was asked to become a pilot to help defend the "White Base" from frequent Zeon attacks. Kai was assigned to pilot the RX-77 Guncannon mobile suit, the unit he would remain in charge of for the rest of the One Year War.