|Manga Debut||Round 77|
|Anime Debut||Round 26 (The Fighting)|
As mentioned by Kumi, Tanaka is a kind person who offered to help the Mashiba siblings when they needed him the most, and has not fired Mashiba despite his behavior. He is shown to be a very calm and comprehensive man, who sees beyond appearances and notices the good inside Mashiba.
He is first seen with Mashiba at their job, when Kumi drops by to deliver Mashiba's boxing gear before gym training.
He is also present at the East Japan Rookie King Tournament finals, where he watches Mashiba's match with Kumi. Despite their cheers, Mashiba ends up losing the fight.