Tamayo is 12 years old and is a friend and classmate of Misaki. She nicknames Misaki "Misakichi" and is rather eccentric. One of her favorite activities is practicing her martial arts techniques on her unwilling friend Kotaro. She always loudly cheers for Misaki at Angelic Layer matches and defends her against those who question her ability. It is later revealed that Tamayo has always held intimate feelings for Kotaro, which may be one reason why she always added "chan" (which Kotaro complains is only meant for "girls and little kids") to the end of his name instead of "kun", despite him being in middle school. She offers to be Misaki's "second" in her national game match against the Angelic Layer Company's angel due to Hatoko becoming ill before Misaki accepts Ohjiro's offer to be her second.