Osha was found as one of the three regional Starter Pokemon a new trainer could choose. In The Battle Starts Here!, he was later chosen by Vincent due to its cuteness and the strong-willed spirit it has despite Dwayne calling it weak and too childish which angered the Sea Otter to run away. When Vincent found him, they were ambushed by two Liepard. After saving him, Osha defeats the two Pokemon with Water Gun and then accepts its new trainer who was different from Dwayne however.
In Oshawott's Nickname!?!, Vincent named him Osha due to the first haldf of his name to the Sea Otter's amusement. he later battled against a wild Excadrill and manages to activate Torrent when he was subdued by Sandstorm and Metal Claw.
In A Glimpse of Team Plasma!, he fought against N's Purrloin during Ghetsis' speech on liberating trainer's Pokemon. Later in Lessons of Listening, he manages to use its ability Torrent which helped him learn Razor Shell. But since he was unable to copy its speedy reflexes, he fell simultaneously in the aftermath.
In The Trio Battle!, he participated in his first Gym battle against Striaton Gym Leader Cilan and his Pansage. Despite his type dis-advantage against Pansage, he managed to defend himself from Vine Whip and countered Seed Bomb with Water Gun, he finally defeats the Grass Monkey, enabling Vincent to earn the Trio Badge.
In A Vital Rival Comeback!, he fought against Dwayne's Snivy and Krokorok in Vincent and Dwayne's first battle. Despite its type-disadvantage with Snivy, he managed to counter Leaf Tornado and defeats the Grass Snake who used Cut. But when he battled Krokorok, despite the type advantage he had, he then lost to his opponent whom had higher levels of power since evolution.
|Water Gun+||The Battle Starts Here!|
|Tail Whip||Oshawott's Nickname!?!|
|Razor Shell+||Lessons of Listening|