Alright, I don't feel too comfortable bunnying your character, so I'll leave the interaction between the rhyfamily and your character to you. Feel free to bunny my character to get there.
After being explained the situation, Kaizah would saybe pretty simple and say something along the lines of "You can't just let those two just throw you around like that, go talk to them, now." He isn't the wordiest person. He'll of course come to support Hiro and when the suggestion of fighting comes along, he'll be all up for it.
Just read your post and I just wanted to clarify the direction you wanted it to head.
Kaizah's naturally accept Hiro help, ask what happened, and presumably get his answer. He'll ask if Hiro is just going to be okay with being thrown around like that and suggest talking to the rhyduo.
From there I figured it could go in two different directions depending on the Rhyfamily personas, if they are arrogant they'll act as if they aren't as fault and eventually in get a fight between (in which they'll get beaten), if they are nice they'll apologize and suggest a friendly sparring match (in which they'll also get beaten), both ways we get a fight and a bonding moment for the characters to get to know each other.
From there I would guess the other character who want to meet up with Hiro could pop up witnessing the sparring match and becoming interest in speaking with him.