Kibitoshin is the resulting fusion of the Eastern Supreme Kai, known as Shin, and his attendant, Kibito, created when they each put on one of the magical Potara earrings. This event occurred during the battle against the evil wizard Majin Buu. Both Shin and Kibito were unaware that the fusion performed with the Potara was permanent, unlike the Metamoran fusion dance, leading to Kibitoshin replacing the two separate beings for a significant period. After the fusion, the Elder Kai, an ancient and perverted former Supreme Kai, scolded them for their recklessness but also prevented the newly formed Kibitoshin from joining the fight out of fear that he would only be absorbed by Majin Buu.

In terms of personality, Kibitoshin largely retains the consciousness and demeanor of the Eastern Supreme Kai, Shin, as he was the higher-ranking deity. As a result, the fused being is responsible, somewhat anxious, and carries the weight of his divine duties. He also retains Kibito's loyalty and his sense of propriety regarding the sacred realm of the gods. However, the fusion also inherits Kibito's more pragmatic and sometimes dismissive attitude towards mortals, a trait that would later be noted in the Dragon Ball Super manga when Shin mentioned that Kibito harbored some distrust of mortals. This suspicion would ironically make Kibito a brief, comedic suspect in the eyes of the God of Destruction Beerus, who wondered if Kibito could be the mysterious villain Goku Black.

Kibitoshin's primary role is one of support. Combining Shin's knowledge of the universe's divine hierarchy with Kibito's magical abilities makes him an invaluable asset. His most notable power is a form of teleportation known as Instantaneous Movement, which differs from Goku's Instant Transmission. This divine ability allows him to move instantly to any location in the living world, the afterlife, or even to the realm of the gods without needing to lock onto a specific energy signature. It is a faster and more versatile method of travel. He also possesses Kibito's healing ability, which can restore a person's energy and heal their wounds. During the final battle against Kid Buu, Kibitoshin uses this teleportation power to rescue Goku, Vegeta, Dende, and Mr. Satan from Earth just before it is destroyed, transporting everyone to the safety of the Sacred World of the Kai.

The key relationships of Kibitoshin are largely inherited from his two components. He maintains a respectful, if sometimes strained, relationship with the perverted and wise Elder Kai. He also acts as a divine observer to the Saiyans and other Earth's protectors, developing a particular respect for Gohan after witnessing his potential. For the remainder of the Majin Buu saga, Kibitoshin acts as a spectator and transporter, watching the final battle against the original form of Majin Buu from the sidelines.

The development of Kibitoshin continues into the series Dragon Ball Super. Despite the previous belief that Potara fusion was permanent, it is revealed that Shin and Kibito have used the Namekian Dragon Balls to defuse back into their original forms. The reason given for this is simply that the fused state felt strange or was for practical purposes, indicating that while the fusion was powerful, they preferred their individual identities. This act of defusing effectively ends Kibitoshin as a permanent character, reverting him to the separate duo of Shin and Kibito. As separate beings, Kibito continues to train with Shin and even spars with the apprentice Supreme Kai Zamasu, proving to be a skilled but not exceptional fighter. The narrative choice to separate them highlights their individual development and allows Shin to take a more active role as a guide in the new cosmic conflicts, while Kibitoshin remains a notable example of the complex and sometimes humorous consequences of divine artifacts.