Digimon Adventure V-Tamer 01

Digimon Adventure V-Tamer 01 (デジモンアドベンチャーVテイマー01) was the first and longest-running Digimon, printed in the pages of magazine. Starting on November 21, 1998, it ran to fifty-eight chapters and ended on August 21, 2003. This manga introduces the character of Tai Kamiya, an alternate Tai to the one that features in the Digimon Adventure TV series.

Plot
In this universe, Tai is involved in a V-Pet tournament, where he is told he cannot play because the Digimon in his V-Pet isn't recognized as being a real Digimon. However, after the tournament is over, Tai plays the winner of the tournament, a boy named Neo Saiba. Their battle ends in a tie—something that is supposed to be impossible. Later, Tai is summoned to the Digital World by a digimon called Lord. There he meets the mysterious Digimon in his V-Pet, Zeromaru the Veedramon. Tai and Zeromaru travel to Lord MagnaAngemon's castle with the aid of Gabo the Gabumon. There Lord MagnaAngemon begs Tai to find the five V-Tamer Tags and defeat the evil, who has disrupted the peace of the Digital World.

Along the way, more Humans are brought to the Digital World by Daemon, including Sigma, Mari Goutokuji, Hideto Fujimoto, Neo and Rei Saiba. Neo is chosen to raise the Digimon that will hatch from the Ultra egg Daemon is raising. Rei Saiba, Neo's sister, has a that will allow Daemon's experimental Digimon to Digivolve to a level beyond Mega. The others, called the Alias III, are to help Neo and Daemon with their Digimon. Hideto's Partner is, formed by the Jogress of Warg and Melga, a WarGreymon and MetalGarurumon respectively. Mari's Partner is a and Sigma's is a. They are all villains that eventually reform except Rei, who has no Digimon Partner or evil intentions.