Kasai was the son of a trusted SkyWing soilder, who was treated as a noble and welcomed to live in the palace for his contributions and service to the Sky Kingdom. He was very young when they moved into the palace, so it wasn't to difficult for him to adjust. Kasai was a curious, thoughtful dragonet who enjoyed poking his nose where it shouldn't be.

He met Prince Falcon during this time, and the two became very close. He and Falcon were inseperable, considered troublemakers in the palace and regarded with fond frustration. The duo spent a lot of time doing (usually) harmless pranks, sneaking food from the kitchens, and goofing off from their schooling.

Just before Prince Falcon was to turn seven and attend his coming-of-age ceromony, there was an attack on the Sky Kingdom. NightWing assassins came to disrupt the order (and perhaps incur a new war) by killing the SkyWing heirs.

While Prince Jasper and Princess Flicker made it to safety, Prince Falcon had been outside the palace goofing off with Kasai at the time. The palace gardens were set ablaze by the NightWings, using the smoke to conceal themselves as they approached the unguarded prince. He and Kasai were cornered against a wall of flame by one of the NightWings.

Kasai, seeing that their target was Falcon and he was being mostly ignored, lept to save his friend. He tumbled back into the flames with the NightWing, screaming for Falcon to flee as he held the assassin in the fire. The two would burn up in the flames but, miraculously, Kasai would survive, but only because of Falcon's insistance that guards return to the garden to save him (risking his own life if they refused to do so).

Kasai was badly burned, and very little was left of the NightWing. It was theorized that the body of the assassin took the brunt of the flames, though Kasai was still left disfigured. His hind legs, not protected by the NightWing's bulk, were too badly burned to be of use and were amputated.

He now spends all of his time being cared for by nurses at a SkyWing hospital. He needs round-the-clock care because of the severity of his burns, though he tries his best to retain some independance. Falcon visits him weekly (or more, if he can manage) and oversees his care. He often brings Kasai gifts of treasure, which are usually rejected.

Although he feels his life was cut short, Kasai is still happy to have survived. He's happy he could save his friend, and knows that Falcon will always come through for him in the end.