Kai Hiwatari (Manga)

In the manga, a lot more is revealed of Kai's past. His father's name is Susumu Hiwatari, and little is seen of his mother.

Kai is even nastier than in his initial anime appearance. It is revealed that Kai, as a child, had a very close relationship with his father, a man who enjoyed engineering beyblades. The two played many battles together, delighting the young Kai and making him adore his father. However, when Kai's grandfather, Soichiro Hiwatari, learned of his son's playing rather than working, he dragged him and Kai both to his office at Hiwatari Enterprises. There he issued an ultimatum to Kai's father – to abandon his silly love for toys, or lose his position as heir to Hiwatari Enterprises. Kai's father chose beyblades, voicing a desire to make children smile as his reason.

Kai tried to go after his father as he walked away, but was held him back by his grandfather. At the tender age of ten, Kai took this to be rejection by his father and takes it upon himself to change his attitude. Donning face-paint, Kai begins his quest to destroy beyblades – the toys that 'stole' his father away. While his mother is present at the confrontation in the office, she seems to serve no role, neither aiding nor trying to prevent this rebellion.

Later, during Kai's and Tyson's battle in the regional championships, Voltaire turns up, demanding that the tournament be stopped. At this Kai's father steps in and tells him to leave Kai alone. Throughout the manga – unlike in the anime – however, Kai shows little personal development. His attitude remains largely coldly indifferent.

His rivalry with the Majestics team member lies with Robert rather than Johnny although like the anime he does lose to Johnny just before he demands to another battle in which Robert volunteers. The first time Kai faces Robert he loses horribly. The next time he faces Robert was in the world tournament which proved to be one of Kai's hardest battles at that point though in the second match he defeats Robert once again and claims that he can't stand the idea of anyone being better than him.

In the Beyblade epilogue, Kai is married to an unknown and unseen woman, with whom he has a son named Gou (Goh) Hiwatari, who is seen blading with Makoto, Tyson's son. Gou has an uncanny resemblance to Kai.