Ken was the last new digidestined to join the team. His story is quite different from that of the others.

Ken was the perhaps the first of the current digidestined to go into the digital world. When he was young, a digivice came through the computer. His older brother Sam thought the digivice was meant for him and told Ken not to touch it, but Ken did, and went into the digital world where he met his partner Wormmon.

Young Ken was a gentle child who was constantly overshadowed by his older brother, a well-mannered genius. It seemed like his parents loved Sam a lot more. After his brother died, Ken embraced the evil powers that made him a prodigy too. (At least I think this is what happened.) He became a genius in his own right, as well as an awesome soccer player, judo champion and computer expert.

However, although he was greatly admired by everyone, Ken was not a nice person. He thought himself greatly superior to everyone, sneering at them behind their backs and feeling disgusted that he had to live in this world with so many idiots.

In fact, as Ken had a digivice - a dark digivice, in fact - he could go into the digital world like any of the digidestined. He set himself up as the cruel Digimon Emporer and went about taking over the digital world, enslaving and controlling helpless Digimon.

His dark digivice was powerful enough to negate the effects of normal digivices - ie, it prevented Digimon from digivolving. That is why the new team of digidestined were called, as they had the power to use digieggs for armour digivolving.

The Digimon Emporer enjoyed his reign of terror for some time, eventually giving up his life as Ken Ichijouji to live in the digital world full-time. He played with the powers of darkness, ignoring his one faithful friend, Wormmon, and attacking the digidestined at every turn.

After the digidestined, with Wormmon's help, defeated the Emporer's trump card, Wormmon died. It took the death of his one friend, who had always hoped that Ken would return to his old, kind self, to restore his senses. The evil that had been in the Emporer suddenly dissipated, leaving Ken in horror at the terrible things he had done.

Ken was then his normal self, trying to live with the terrible guilt. He was one of the digidestined, but most of the team was reluctant to forgive him easily. Ken, reunited with Wormmon, started to go off alone trying to right some of the wrongs he had done. He didn't want to join the digidestined team. Perhaps he felt he didn't deserve their friendship.

The real Ken is a kind, gentle person who, in fact, possesses the Crest of Kindness (whether this crest does anything, I don't know ^^;) and is a rather quiet, shy individual. After relinquishing his evil powers, he loses his superior intelligence and becomes a normal kid. But his parents are so happy to have him home again, they realise they were wrong in putting expectations on him, and just love him for who he is.