From Bulbapedia, the community-driven Pokémon encyclopedia.
Pokémon Adventures (Japanese: ポケットモンスター☆SPECIAL Pocket Monsters ☆ SPECIAL) is a manga series authored by 日下秀憲 Hidenori Kusaka and illustrated by 山本サトシ Satoshi Yamamoto and by 真斗 Mato before volume 10. It is published by Shōgakukan under the Ladybird Comics Special series. The series is popularly known as Pokémon Special, and affectionately abbreviated as PokéSpe (Japanese: ポケスペ PokeSupe).
The series was published in the United States in English by VIZ Media, yet publication stopped midway in its run. The series is published in Singapore in English by Chuang Yi.
Creator of Pokémon Satoshi Tajiri is quoted recommending this on volume 1:
- This is the comic that most resembles the world I was trying to convey. 
Red, Green & Blue chapter (Volume 1~3)
Main article: Red, Green & Blue chapter (Special)
The RGB chapter features the journeys of Red and Green through Kanto, conquering the eight Gyms and the Pokémon League. Later, a third trainer, Blue, comes into the plot. Together, they destroy Team Rocket, an evil organization which uses Pokémon for illegal actions. There are also adventures of Red helping Blaine to capture Mewtwo and saving Yellow from wild Pokémon in Viridian Forest. At the end, Red defeated Green in the Pokémon League.
Yellow chapter (Volume 4~7)
The Yellow chapter starts 2 years after Red obtains his title of the Champion in the Pokémon League. Red disappears for one month after he leaves to answer a challenge from someone named Bruno. One day, Professor Oak discovers Red's Pikachu, Pika, injured at his doorstep. Soon after the arrival of Pika, a young trainer comes into the Professor's lab. The trainer, Yellow, claims that "he" is a friend of Red and wishes to look for him with Pika. While Professor Oak is still skeptical about Yellow, especially about "his" ability of healing and sensing Pokémon's emotions, he eventually entrusts this mission and Red's upgraded Pokédex to the young trainer. However, this event only triggers the revelation of a larger secret as Yellow is repeatedly attacked by members of the Elite Four.
Gold, Silver & Crystal chapter (Volume 8~15)
As peace is returning to Kanto, new journeys and happenings are beginning in another region, Johto. Gold was enjoying his normal life with his family Pokémon, who have been with him since birth, until he ran into a Pokémon thief at Professor Elm's lab. As he goes on a journey of chasing the thief, Silver, with a Cyndaquil from Professor Elm and Pokédex from Professor Oak, he stumbles upon the secret plots of the Mask of Ice. At the same time, Professor Oak sends out a "Pokémon Capture Professional", Crystal (Kris), on a journey of completing the Pokédex. She gets involved in Eusine's plans to capture Suicune and tries to do so herself. Soon after, she also gets involved with the plots of Mask of Ice, who is apparently after the two legendary Pokémon, Lugia and Ho-Oh. The more shocking revelation follows: this Mask of Ice is actually one of the 16 Kanto/Johto Gym Leaders!
Ruby & Sapphire chapter (Volume 15~22)
Things have just settled down in Kanto and Johto, but another new region coming on screen. This chapter is about the "rivalry" of Ruby and Sapphire, who are trying to conquer all the Pokémon Contests and Gyms in Hoenn respectively within the span of 80 days. Just like their counterparts in Kanto and Johto, they encounter two evil organizations, the land-loving Team Magma and sea-loving Team Aqua. However, on top of gym battles, her disapproval for Pokémon contests, the two teams and the balance of nature, Sapphire has to worry about something else, too: her feelings for Ruby...
FireRed & LeafGreen chapter (Volume 22~26)
The FRLG series continues the series featuring the characters Red, Green & Blue as they are forced to explore the Sevii Islands to look for Professor Oak who got kidnapped by some unknown Pokémon.
Battle Frontier chapter (Volume 26~?)
The Grand opening of the Battle Frontier takes an unexpected twist when Emerald appears on the scene. Now he must conquer the seven facilities in seven days. With a seemingly unmatched ability at battles and access to every Pokémon Crystal has ever caught, the mysterious stranger that attacks Noland and is seeking Jirachi may be more of a worry.
Diamond & Pearl chapter
A important family from the region of Sinnoh sends their last descendent Berlitz, to an special mision with two peculiar bodyguards, Diamond and Pearl, whose goal is to travel to Mt. Coronet and receive a big prize from Berlitz's family, but it won't be easy.