Klaus is the warrior of the Warlord DigiDestined and DigiDestroyed. He is the son of Jessibelle Hayashi and Radley Kozu. Klaus discovered the DigiWorld when his best friend, Midori Kobayashi, downloaded a virus containing Lucemon. Klaus' parents divorced when he was still a baby, and left him never knowing about Skylar Hayashi, his brother until Klaus questioned Radley about a photo containing him and Skylar. Klaus is first shocked to discover the existence of his brother, but admits that he found out via their father. Klaus was on the DigiDestroyed team, until Lucemon Chaos Mode teamed up with the Seven Great Demon Lords and betrayed Klaus and Midori. Klaus is partnered to Dorumon and they are known to be close with one another, despite Dorumon's "Death" Forms. He has a very close bond with Midori, and at the end of the series, they are a couple. Klaus owns the Crest of hope, which defines him because he's searching for hope to win against the enemies.