In the Manga, Tenmaru Shishi is Kennosuke's younger brother, and always helps him with his training. So, 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. Tenmaru really looks up to Kennosuke; he always follows him everywhere, he gives Kennosuke all he needs, he refers to Kennosuke as "Big Brother", even when talking to him directly. He owns Thunder Dragon MS, which Kennosuke builds for him. He uses it in his match with Daichi.