Name: Blue Oak
Age: 16
Gender: Male
Hometown: Pallet Town
Best personality describing the character: Snob
Like/s: Exasperating other people
Dislike/s: Getting compared to Red, "Pesky Girl" Green
Goal/s: To reclaim the title as the Kanto Champion by defeating Red
Debuted in: Prologue (HiaS)

Appearance:
Blue is a tall young man with brown spiky hair and blue eyes. He's wearing a black leather jacket, khaki colored pants and dark shoes.

His natural foxy face is one of his best assets in which Green find it attractive to him.

Affiliations:
Professor Oak - Grandfather
Daisy - Elder Sister
Red - Childhood Friend / Rival
Green - Childhood Friend / Romantic Interest
Yellow - Childhood Friend

[Spoiler Free]
Blue is the grandson of the famous Professor Oak. He took the position of being the Viridian Gym Leader after he lost his championship to his rival, Red.

He exhibits a rude behaviour sometimes but even though he doesn't show his compassionate side due to pride, he extremely cares for his friends especially Green even he find her sometimes annoying.

As a Pokémon Trainer, she slowly learned the ethics of establishing a powerhouse team that helps her to conquer all the 8 Gyms of Kanto. She's very caring towards them and has a close relationship to her very first Pokémon, Chuchu.

Pokémon:
Squirtle -> Wartortle -> Blastoise
Nickname: -
Gender: Male
Shiny: No
Debuted in:
Off-screen (as Squirtle and Wartortle)
Chapter 4 - Intrepidity and Trepidation (as Blastoise, mentioned only)