Taiju is a friend of Senku and has a crush on Yuzuriha. Taiju has a strong and sturdy body and helps Senku with hunting and carrying heavy items. He is very enthusiastic even about little tasks and is seen screaming a lot. Taiju doesn't like to fight, so he only blocks his opponent's attacks.

Just before the world turned to stone he was about to confess his feelings to Yuzuriha after 5 years because he couldn't get himself to do so before. As he was turned to stone, he survived on his determination to never give up since he failed to tell her how he feels.