In a flashback in Staff Roll 2, Moe's siblings appear and ask for some meat, a teddy bear, and a Game Boy Advance, but Moe could not get them those things because they didn't have any money. Moe thought of finding treasure to get money, so outside of his house he wondered where to obtain it, but couldn't think of anything. Moe was sidetracked after he saw Ruby and followed her instead. Later after Starfy defeated Ogura, Moe was rewarded with Treasure for helping Starfy. Moe then uses the treasure to get the things his siblings wanted. They all dance happily afterwards.
A purple Game Boy Advance appears on the floor in Moe's House. The player must select it to view the minigames menu. Another Game Boy Advance appears in Jojiro's Shop, where a Sand Snark plays it. After the player purchases every item from Jojiro's Shop, he or she can see the Sand Snark playing with the Game Boy Advance anytime by selecting the 'Playing...' (あそんでるよ...) option.
A Game Boy Advance appears in the Human World, where it was owned by Takeo in chapter one of volume one, Going to the Human World Fii! until the Jar fell from Pufftop and landed on it, breaking it. Afterwards, Takeo saw a shooting star and wished that the Game Boy Advance would be fixed, however, the 'shooting star' falls into Takeo's face and turns out to be Starfy.
Takeo saved up much of his pocket money to earn the Game Boy Advance. He was going to show it to Rumi-chan (who he has a crush on) until it broke. Takeo commented that he wouldn't give the Jar back to Starfy and Old Man Lobber until they compensate for the Game Boy Advance. Takeo believed that Starfy was actually a robot after Starfy joked that he would transform into a games console earlier, though he finds out that he isn't in chapter two, I'm a Prince Fii! after Takeo searched Starfy for a 'switch' but tickled Starfy causing him to fart.
In chapter 3, Not Afraid of Water Fii!, Old Man Lobber says that Starfy was busy repairing something yesterday and Takeo wonders if it is his Game Boy Advance. When Takeo arrives back in the Human World from Starfy's world, he finds out that Starfy has left a letter, apologizing for having broken his Game Boy Advance in chapter one. Starfy left Takeo his Game Boy Advance fixed for him and Takeo starts to cry because he is lonely. Though the Game Boy Advance was fixed the portal started to open again and Boctopus fell through it, breaking his Game Boy Advance again.
The Game Boy Advance appears in one cartoon in Starfy Four Cell Theater called "Twice of Anything". In "Twice of Anything", Starfy gets his Game Boy Advance out and talks about Densetsu no Starfy 2 that Starfy says is double the fun. He goes to put it in his Game Boy Advance, although the cartridge appears to be too big.