The first half of this manga was great. However, this is one of those aggravating series which completely changes story & plot in the middle. After the initial plot concludes, a new & almost completely unrelated one ensues. In the second plot, Dragon Drive has been transformed into a card game and the star is a completely new character (although I believe he's related to one of the original heroes). The only returning character in the beginning is the announcer, Agent L.
Some of the original characters do return much, MUCH later in the series, but even then they're little more than cameo appearances.