Following the name of the champion(s): Indicates the number of times the competitor has held that title at that point.
[...]
Indicates a gap in the listing where title changes are not known.
<
Title was held or changed hands no later than this. In these cases, it is known that a competitor held the title at a certain time but not when he/she won it.
@
Order uncertain. Different titleholders may be known for the same year, for example, but it is not known who held the title before whom.
#
Unofficial or disputable claims. These are usually matches that certainly took place, but where there is doubt that the competitor shown should be recognized as a true title holder. These listings are also italicized.
Defeats Horikawa Ken-ichi; vacates on 15-06-20 to challenge for the world title; wins WBC World Title on 15-11-28.
Horikawa Ken-ichi
2015-09-17
Ōyamazaki, Kyōto
Defeats Ono Shin.
Kenshirō (Teraji Kenshirō)
2015-12-27
Kyōto
Also wins OPBF Title 16-08-07; vacates both titles on 17-03-21 to challenge for the world title; wins WBC World Title on 17-05-20.
Hisada Tetsuya
2017-04-21
Ōsaka
Defeats Horikawa Ken-ichi; vacates on 18-12-05 to challenge for the world title.
Horikawa Ken-ichi [2]
2019-02-14
Tōkyō
Defeats Todaka Satoru.
Takahashi Yūto
2019-10-10
Tōkyō
Retires on 20-04-03.
Yabuki Masamichi (Satō Masamichi)
2020-07-26
Kariya, Aichi
Defeats Satō Tsuyoshi; vacates on 21-07-21 to focus on challenging for WBC world title; a match between Shiba Rikito and Iwata Shōkichi is scheduled for the vacant title on 21-09-11 but is postponed when Iwata is infected with COVID-19 virus.
Iwata Shōkichi
2021-11-06
Tōkyō
Defeats Shiba Rikito; also wins OPBF and vacant WBO Asia Pacific titles on 22-07-02; loses his bid for WBO world title on 22-11-01; Tomita Daiki and Shiba Rikito fight to a draw on 22-12-04 for the vacant title.
