|First Appearance||Chapter 0|
|Voice Actor||Kiyomitsu Mizuuchi|
Taiji Kokubun (国分 泰治 Kokubun Taiji), also known as the Antique Shop Owner before his name was revealed. He is the owner of the Kokubundo Shoppe where Yamato first encounters Ultimo in the present time. In the Chapter 0, he is shown finding Ultimo in the mountains.
Due to his age, he has a rather short stature with long white hair and beard. He wears a black skull cap with a white skull imprinted on it, a black long-sleeved shirt, and a pair of white pants folded up to his ankles. In almost all of his appearances, he is shown drinking a cup of hot tea.
He is shown to have a very polite and laid-back, philosophic personality, shown when he patiently explains to Rune his reasons for searching the mountain for "trash" to be sold as treasures.
In the mist of tense, shocking events, Taiji's reactions is shown to be very down-to-earth, as when Jealous explodes his shop, he only seemed to be troubled that a "boy turned into a giant spider" than the fact a battle was about to take place and his life was in danger. He, however, was not startled when Yamato and Ultimo became God Ultimo, showing that he is quick at adapting to situations and regain his composure.
|The Good Dôji Club:||Yamato Agari · Shin Ekoda · Yoichi Oizumi · Koun Shakujii · Musashi Murayama · Hiroshi Kumegawa · Machi Shina · Makoto Sayama · Akitsu Otake · Hibari Oume · Kiyose Matsumoto|
|Allies:||Darumada Masami · Hyoe Tokorozawa|
|The Evil Dôji Branch:||K · Akira Hidaka · Kaizo Oume · Fusataro Fussa · Sumako Miyoshi · Mizho · Rune Kodaira · Hana Koganei · Tomomitsu Iruma|
|Unspecified/Neutral:||Roger Dunstan · Miyu Murayama · Taiji Kokubun · Fushimi Agari · Yuu Ekoda · Shinsaku Ekoda · Saishinsaku Ekoda · K's Grandmother|