Kai's name is derived from the name of a World War II era Japanese fighter plane, the Kawanishi N1K2-J Shiden-Kai.
At the onset of the One Year War in UC 0079, Kai Shiden lived 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 around. After surviving the Zeon attack on Side 7, Kai evacuated to the Pegasus class assault carrier SCV-70 White Base to make his escape. However, due to a shortage of crew and soldiers to staff the battleship Kai was asked to become a pilot to help defend the White Base from the frequent Zeon attacks. Kai was assigned to pilot the RX-77-2 Guncannon mobile suit, the unit he would remain in charge for the rest of the One Year War.A natural coward, cynic, and pessimist Kai could often be found hiding on the sidelines making smart-alecky comments. His fighting style leaned towards bombarding foes with the Guncannon's long-range armaments, but when he got in a fix he had shown that he was able to pull off hand-to-hand attacks with the Guncannon. However, Kai quickly became disenchanted with war and he decided to desert the White Base when it was docked for repairs in Belfast, Ireland. Outside of Belfast, Kai met a young girl named Miharu Ratokie, and agreed to sneak her onto the White Base and took her to the Earth Federation headquarters in Jaburo, located along the Amazon River in South America. But unbeknownst to Kai, Miharu was actually a hired Zeon spy sent to infiltrate the White Base and discover Jaburo's location.
During the White Base's travel over the Atlantic Ocean Kai began to have feelings for Miharu. But a sudden Zeon attack on the White Base over the Atlantic forced Kai to take desperate measures to protect the ship, and he and Miharu went out in a Gunperry transport plane. When the Gunperry got damaged, Miharu was forced to help firing the plane's missiles manually, but was knocked from the Gunperry by the missiles' exhaust blast, and fell to her death in the Atlantic Ocean. When Kai returned to the White Base he was much more somber, torn apart on the inside by Miharu's death.
This caused a transformation in Kai. Realizing he could not stay depressed for the rest of his life, Kai came to understand that he had friends to fight for and protect if they were all to survive the war.
After the One Year War ended Kai Shiden became a freelance journalist and investigative reporter. In UC 0087, during the events of the Zeta Gundam TV series, Kai began to investigate the Titans military organization. During a covert mission to discover why the Titans were evacuating their base in Jaburo, Kai met AEUG spy Reccoa Londe who was scouting ahead of a coming AEUG attack force. However Kai and Reccoa were captured by Titans forces and imprisoned in Jaburo. Luckily they were not executed, but unbeknownst to them a nuclear bomb was set as a trap to destroy the coming AEUG forces attacking Jaburo. Fortunately AEUG pilot Kamille Bidan discovered the bomb beneath the base and was able to release Reccoa and Kai in time. With the help of former White Base pilot Hayato Kobayashi the AEUG was able to escape from Jaburo before the nuclear weapon obliterated the base.
Throughout the remainder of the Gryps War Kai took a minor role, coordinating messages between the AEUG and the Karaba resistance group run by Hayato, as well as some slight information gathering.
Role in Super Smash Sisters
Kai Shiden is a young NPC in Super Smash Sisters. When summoned, he pilots his Guncannon mobile suit to battle. His Guncannon uses it's rifle for normal and ranged combat. The Guncannon can also use it's shoulder cannons to blast your opponents.