Yamada Denzou's only son. He is a very competent and respected 18-year-old freelance ninja who's constantly busy with work. Despite his father being a Ninjutsu Academy teacher, he didn't go there himself; however, he does often visit his father at his work, and the students there all look admire him a lot.

Since Ninjutsu Academy is far from their home in Mount Hyono where his mother lives, Rikichi often runs errands between his parents and tries to convince his father to go home more often.