Digimon Tamers: The Runaway Digimon Express

Digimon Tamers (デジモンテイマーズ, Dejimon Teimāzu?) is the third animated series based on the Digimon franchise, first broadcast in 2001. The story takes place initially in the "real" world, a world much like ours where Digimon is just a franchise, composed of video games, a collectible card game, and a cartoon series. A group of 12-year-olds (10-year olds in the Japanese version), Takato, Henry and Rika (fans of the Digimon card game) meet their own Digimon friends and start to duel "bio-emerging" Digimon who cross the barrier between the information network, synthesizing proteins and becoming real. Most of it set in the modern Shinjuku ward of Tokyo, Japan and only changes scenario to the Digital World for a short time.

The tone of this season has many elements from head writer Chiaki J. Konaka's other works, especially Serial Experiments Lain, including a few aspects from Neon Genesis Evangelion. Thus, the series had a very dark tone in nature, much more so than its predecessors. One thing that made the tone darker than previous seasons was that when a Digimon died it turned back into data and could be absorbed by other Digimon, where as in other seasons the Digimon turned back into a Digi Egg and was reborn. The only Digimon of the main characters that actually died was Leomon. The English dub is, to a point, more lightly edited than in previous seasons.

Source: Wikipedia