Kaede grew up with Moriya back in Frostspire, along with Yuki. They became very close, such that called each other brothers and sister. Kaede entered the service of a Frostpirean kami, Seiryuu, a grandchild of the Serpent, who was aligned with lightning and wind, and eventually became his Avatar, much to the pride of his family and friends.
In the last few years, they grew apart, or at least Moriya did, from Kaede and Yuki. A rift even grew between Kaede and Moriya, after Moriya broke Yuki's heart. It was very tragic indeed that it took Moriya's death to bring the two of them back to their brother's side.
Kaede was commanded by Seiryuu to protect Motoko, Bride of the Dragon, now that the Sword, his brother Moriya, was broken, and he went forth to join her, as did Yuki. One of the first things he did in her service was help rescue Jacqueline's daughters from the clutches of Outsider cultists.
He had the misfortune to start falling for Moonshade, the new Sword, and one of Motoko's lovers. This almost caused a falling out, but fortunately, that was averted.
More recently, he has been seen in the company of Princess Nausicaa quite a bit, once she joined Motoko's party in Morgenstern's shadow to prepare for the battle in Chaos and the defense of the High Summer Rites. He along with Nausicaa barely escaped a pretty nasty fate, of being turned into Wu by Wu-Anno, and then vaporized by Primal Chaos.
After the end of the Herald crisis, he and Nausicaa got married.
Kaede was a victim of Nemuro Hall, but fortunately didn't kill anyone. He is now heading into shadow with Akari.
With Nausicaa's death, he has gone into the Dreaming to be with her soul. Whether he will ever return is not known.