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Jou (Japanese: ジョウ Jō) is the main character of Pocket Monsters HGSS Jou's Big Adventure.
Jou is a beginning Trainer who went off to get his first Pokémon in Professor Elm's laboratory. After much consideration, he chooses Totodile. Later, he challenges Falkner where he manages to defeat him, earning himself the Zephyr Badge. Afterwards, he has Totodile take on a wild Bellsprout for training. He meets Tsubaki and has his first rival battle with him. After a long and hard fought battle in which Totodile came out on top, Jou notices that Kurt is in trouble. Three members of Team Rocket along with Proton have arrived to take the Slowpoke in order to profit their tails. Jou watches as the members are arguing with Kurt about how they're doing the right in which Kurt disagrees. Jou arrives and puts a stop to them. The grunts battle him but Proton decides to handle things with him instead. As Totodile got weaker by Proton's Zubat's Wing Attack, the grunts hold Jou back but Totodile goes for a last ditch Scratch which takes out both of Proton's Pokémon.
After Team Rocket retreated empty-handed, Jou meets a Kimono Girl at the Burned Tower. She tells him about the three legendary beasts that reside their at the bottom floor. As soon as Jou went to the bottom floor, Morty arrives and battles Jou. Jou manages to defeat Morty earning him the Fog Badge.
When Jou went to the Lake of Rage, he meets Lance where he tells Jou about a different-colored Gyarados residing in the lake. As soon as the Red Gyarados comes out of the lake, Lance has Jou fly on his Dragonite to safety. Jou then battles the Gyarados with Totodile, feeding the Gyarados berries when it was weakened. However, the Gyarados wasn't ready for the berries and swims off. Jou finds out that Ariana and Petrel were responsible with the Red Gyarados's rampage and battle them. Lance joins in and suggests it to be a Double Battle. During the battle, the Red Gyarados returns and allows Jou to feed it a berry, making the Gyarados happy. Gyarados takes Totodile's place and finishes Ariana's Gloom off. With the two defeated, Jou goes to Team Rocket's hideout.
Jou meets up with the Rocket grunts, including the three he met earlier. The grunts takes him on and Tsubaki arrives with his Meganium. The two Trainers have their second rival battle with Totodile once again winning. After the battle, Tsubaki starts to respect Jou and the two work together to defeat Team Rocket. Archer, who was watching the whole thing, sends out his Houndoom and Jou easily defeats it with Totodile, finishing off Team Rocket.
Jou battles the Johto Elite Four and sweeps the first four members, leaving the Champion left. The Champion turned out to be none other than Lance, the Trainer he met at the Lake of Rage. Both Jou and Lance give it all they got and in the end, Jou emerges victorious. He battles the Kanto Gym Leaders and is left with Blue. After the battle with Blue, Blue suggests him to go to Mt. Silver to meet stronger Pokémon and that a Trainer named Red is on the summit.
Jou heads to Mt. Silver per Blue's suggestion. He battles the wild Pokémon with his Feraligatr, simultaneously defeating them. Jou is last seen where he meets Red at the top of the mountain, battling him.
Jou is a very caring Trainer as seen when he saved Totodile from getting hurt most of the time. He has also done this to a Red Gyarados by feeding it berries.