Tyson's grandfather and a living kendo master.
He welcomed his grandson to his dojo when Yoshie died. He practices swordsmanship, kendo actually, and tries in vain to teach Tyson some things, but the latter has other interests.
The elder Kinomiya is an enthusiastic and energetic character, although more civilised in the Japanese version of the anime (in the English dub, he is the "cool-yo" type). He sometimes follows team BBA around the world to support them during tournaments. In Japan, he also offers a home for the team.

In general, he mostly creates comic relief, but he also occasionally (and involuntarily) makes Tyson realise some important tips for beyblading, such as the winder lengthening trick.

For family reasons, Ryu's dojo also housed the sword-shaped stone inside which Seiryuu was trapped.

In G Revolution, he took the place of the fifth member on Tayson's G Revolutions team as "Mr.X". This was only temporary, because Tyson was looking for the appropriate beyblader to complete his team and Kai was nowhere to be seen, yet the Justice 5 tournament rules required for him to submit a list of players before a certain deadline.