Kukuru was born to Tajikara and Tarane of the Hikari Tribe that originated from a continent that would be known in the present as China. While on a hunting trip with his father, he befriended with a feral wolf cub he named Roo.
During the start of the film, Kukuru went fishing at the river not far from his village, however at the same time his village was attacked by the Dark Tribe and everyone in his village was taken. Kukuru returned only to find that his village has been reduced to ashes, he was then sucked in by a mysterious vortex which transported him to Japan 70,000 years in the future. Kukuru unknowingly took residence on the roof of Nobita's home and secretly stole the Nobi family's food in order to survive. Kukuru experiences a nightmare that showed his village was attacked and that he was unable to save his mother from the Dark Tribe.
The next day, while exploring Nobita's room Kukuru had an unexpected encounter with Jaian and Suneo. He reacts with hostility and attacks them both. However, he was defeated by Jaian. Doraemon and the others took him back to their settlement in prehistoric Japan to treat his wounds and to figure out his origins. Kukuru soon awakens and was kindly greeted by Doraemon and the others. Kukuru tells Doraemon and the others of his origins, as well as the barbaric Dark Tribe and their fearsome leader Gigazombie who have been terrorizing his people. Doraemon and the others offer their assistance to rescue the Light Tribe, but Kukuru declines their offer and sets out to rescue his tribe. Doraemon was able to convince Kukuru that he is a powerful shaman (with the help from his futuristic gadgets) and offers his assistance in defeating Gigazombie. Doraemon and the others eventually reached north and encounter the Dark Tribe and the living claydol Tsuchidama. Doraemon and the others were able to fend off the Dark Tribe and destroy Tsuchidama, Kukuru was reunited with his parents and the Hikari Tribe.
After being transferred to prehistoric Japan, the Hikari Tribe begins to build their new settlement. After Kukuru helped his father built their home, he looks for Nobita who has gone looking for Pega, Gris and Draco. Kukuru was able to find Nobita who is worried about Pega, Gris and Draco and comforts him with a story about his wolf cub Roo. The following night, Kukuru and the Hikari Tribe held a celebration in honor of Doraemon and their new home. The next day, Kukuru bids farewell to Doreamon and co and assures Nobita that he will take good care of Pega , Gris and Draco when they return. However, the Dark Tribe manage to locate the Light Tribe's new village and attacked it, resulting in his mother to be injured. The Dark Tribe soon abducted everyone, including Kukuru. Kukuru, his parents, along with the rest of the Hikari Tribe were soon brought to Gigazombie's temple the Tokoyomi Shrine in the north and were forced to work as slaves.
Doraemon and the others headed North to rescue Kukuru and the Light Tribe, but lost Nobita in the blizzard. They took refuge in a cave, which happens to be the entrance to Tokoyomi Shrine and was able to locate Kukuru and the Light Tribe, who were being enslaved. Doraemon used his Ultra-time watch to stop time and confront Gigazombie, but was defeated by him. Thanks to Nobita and the future police, Doraemon, the others and the Light Tribe were rescued and Gigazombie was captured. Kukuru bids farewell to his friends and continues a peaceful life with his parents and the Light Tribe. 20 years later, Kukuru grew up strong and became the chieftain of the Light Tribe. His name was changed to "Unbaho" ( meaning The Brave of the Land of the Sun) and was respected by the Hikari Tribe.
- It was revealed in the second chapter of the Chinpui manga (another work by Fujiko F. Fujio) that Kukuru is Eri Kasuga's ancestor.