He owns Thunder Dragon MS, which Kennosuke builds for him.
Kennosuke Shishi is Tenmaru older brother. Kennosuke always helps him with Tenmaru with his training. Tenmaru really looks up to Kennosuke; he always follows him everywhere, he gives Kennosuke all he needs, he refers to Kennosuke as lder Brother, even when talking to him directly.
Whenever Daichi comes to bother them, Tenmaru asks Daichi to go away and leave them alone, while Kennosuke just advises his brother to ignore Daichi.
He verses Daichi in a match.