In the Prime Empire Original Shorts episode "Upgrade", the Mechanic is able to pull off a successful heist and upgrade his robotic arm with help from Unagami, who communicates with him through a computer. Though initially refusing to reveal anything about himself, he eventually reveals his name to the criminal; he also notes that they will soon be able to accomplish something even more significant.
In "Would You Like to Enter Prime Empire?", Unagami sends the Mechanic and his gang on a mission to recover a strange motherboard. It is confiscated by the Ninja, but Jay inserts it into an old Prime Empire terminal in the Mechanic's hideout, thus fulfilling Unagami's plans. The other Ninja find Unagami's communication terminal and learn his name, but nothing else about him.
In "Papergirl", Unagami-still in his child form-is seen living in Ninjago City, and waves to Antonia and Nelson after receiving a paper from them. In “The Turn of the Tide”, Unagami is among the Ninjago Island residents who appear at the ceremony honoring Nya.