MegaMan NT Warrior

In the year of 20XX, a young boy by the name of Netto Hikari receives a very special gift as he enters the 5th grade. His very own customized net navi, Rockman! Despite Rockman's small size and far more responsible personality, the two boys quickly become the best of friends. A net navi is designed to guide his operator from the inside of his or her PErsonal Terminal, or simply PET for short. Children and adults alike enjoy friendly "Net Battles", where they spar their navis against each other to prove their worth. (Source: Official Site)

Battle Spirits: Strongest Galaxy Ultimate Zero

Saikyou Ginga Ultimate Zero: Battle Spirits is an anime inspired by Bandai's Battle Spirits trading card game and produced by Sunrise. It is not related to any previous Battle Spirits anime work. Rei is an adventurer called a "Card Quester." He wishes to collect strong cards scattered throughout space, and a battle with his rivals unfold. (Source: Battle Spirits Wiki, ANN)

Digimon Frontier

Takuya Kanbara is an average city kid who receives a text message from an unknown source instructing him to "board a train towards his destiny". Taking up the Call to Adventure, he finds the train in question and is whisked off to the Digital World, which is currently under threat from the malevolent Cherubimon. Cherubimon and his minions are consuming the very building blocks of the Digital World (its "Fractal Code") to increase their own power, and if nothing is done then the entire Digital World will be devoured. All is not lost, however. Takuya and the other "chosen" children who boarded the train inherit the power of the Ten Legendary Warriors that saved the Digital World in the distant past, allowing them to transform themselves into Digimon. With their new powers, they fight to take back the stolen Fractal Code and restore the fractured Digital World to its former glory. (Source: TV Tropes)