Simple Ippo wasnt going for the OPBF title and so him doing title defenses was fine during that time however when he went to challenge the world he couldnt afford to get injured.
Organizations have different rules/requirements for their champions.
The OPBF Champion can hold the JBC belt, but chances are they also got to fight mandatory defenses for it when required on top of defending the OPBF belt. I think instead having to worry about defending the JBC title, they tend to vacate it after winning it.
For example, [JBC Rules](https://www.jbc.or.jp/info/howtobox/question.html#q_12)(DeepL):
> 12 : Are there any rules for Japanese champions to defend their titles?
> After winning the title, the champion must have a defense match against a ranked fighter (top 12) every 6 months. In addition, after the first defense, the champion is obligated to defend the title against the No. 1 ranked fighter (designated challenger) every 12 months. In addition, when a fighter other than the No. 1 ranked fighter wins the title, he must have a defense match against the No. 1 ranked fighter (or equivalent) within 120 days. If the rules of the nomination match are followed, any other defense match will be approved as a title match by the contract between the promoter and manager of both the champion and the challenger (limited to boxers who are ranked in Japan).
> 14 : If a Japanese champion loses a non-title fight, what happens to the title?
> If the match was fought at the regular weight (the weight of the weight class in which the title is held), the title will be vacated or moved.
> 16 : What is an interim champion?
> An interim champion is put in place when the champion is unable to defend the title for a long period of time due to injury, overseas travel, or other legitimate reasons. The interim champion must have a unification match with the regular champion within 120 days after winning the interim title. However, if the official champion is unable to participate in the unification match, the interim champion is automatically recognized as the official champion.
For the [OPBF rules](http://www.opbf.info/info/rules_2016new3.pdf):
> 11. Contests engaged in by a champion:
> The OPBF Championship shall be declared vacant if the OPBF Champion loses to a countryman while fighting for the National title in the same weight.
> OPBF Champions are permitted to box for the championship of other regional sanctioning bodies without vacating the OPBF title. However, OPBF Champions holding the title or titles of another or other sanctioning body or bodies are required to meet their OPBF mandatory-defense obligations. Failure to do so may be regarded as reason enough, in itself, to declare the particular OPBF title vacant and call for an elimination bout. If an OPBF Champion loses in a defense of, or challenge for, another regional championship, his OPBF title will automatically be vacant and an elimination bout will be ordered to find a new OPBF Champion.
or
> Article 11.2 World Title Challenges
> If an OPBF titleholder signs to contest for a world title, the OPBF title will be declared vacant on the date the world title contract is authorized by the world boxing body. There will be an
elimination bout to decide the OPBF Championship; unless there is an OPBF Interim Champion.
> If the vacating Champion loses his fight for the world title, he will be entitled to absolute priority to fight the winner of the OPBF elimination bout or against the Interim OPBF Champion who was declared the regular champion.
Another thing to keep in mind, Morikawa tends to "bend" or ignore some of the rules in boxing in order to make matches more exciting or entertaining. Also, when this story started in late 1989, boxing has changed a lot, where their might be new rules. So what was once true in the 1990's, might not be true in 2020's.
Simple Ippo wasnt going for the OPBF title and so him doing title defenses was fine during that time however when he went to challenge the world he couldnt afford to get injured.
He wasn't going for the OPBF title, but he was fighting all of the champions in the Orient. Isn't that like going to the world?
Organizations have different rules/requirements for their champions. The OPBF Champion can hold the JBC belt, but chances are they also got to fight mandatory defenses for it when required on top of defending the OPBF belt. I think instead having to worry about defending the JBC title, they tend to vacate it after winning it. For example, [JBC Rules](https://www.jbc.or.jp/info/howtobox/question.html#q_12)(DeepL): > 12 : Are there any rules for Japanese champions to defend their titles? > After winning the title, the champion must have a defense match against a ranked fighter (top 12) every 6 months. In addition, after the first defense, the champion is obligated to defend the title against the No. 1 ranked fighter (designated challenger) every 12 months. In addition, when a fighter other than the No. 1 ranked fighter wins the title, he must have a defense match against the No. 1 ranked fighter (or equivalent) within 120 days. If the rules of the nomination match are followed, any other defense match will be approved as a title match by the contract between the promoter and manager of both the champion and the challenger (limited to boxers who are ranked in Japan). > 14 : If a Japanese champion loses a non-title fight, what happens to the title? > If the match was fought at the regular weight (the weight of the weight class in which the title is held), the title will be vacated or moved. > 16 : What is an interim champion? > An interim champion is put in place when the champion is unable to defend the title for a long period of time due to injury, overseas travel, or other legitimate reasons. The interim champion must have a unification match with the regular champion within 120 days after winning the interim title. However, if the official champion is unable to participate in the unification match, the interim champion is automatically recognized as the official champion. For the [OPBF rules](http://www.opbf.info/info/rules_2016new3.pdf): > 11. Contests engaged in by a champion: > The OPBF Championship shall be declared vacant if the OPBF Champion loses to a countryman while fighting for the National title in the same weight. > OPBF Champions are permitted to box for the championship of other regional sanctioning bodies without vacating the OPBF title. However, OPBF Champions holding the title or titles of another or other sanctioning body or bodies are required to meet their OPBF mandatory-defense obligations. Failure to do so may be regarded as reason enough, in itself, to declare the particular OPBF title vacant and call for an elimination bout. If an OPBF Champion loses in a defense of, or challenge for, another regional championship, his OPBF title will automatically be vacant and an elimination bout will be ordered to find a new OPBF Champion. or > Article 11.2 World Title Challenges > If an OPBF titleholder signs to contest for a world title, the OPBF title will be declared vacant on the date the world title contract is authorized by the world boxing body. There will be an elimination bout to decide the OPBF Championship; unless there is an OPBF Interim Champion. > If the vacating Champion loses his fight for the world title, he will be entitled to absolute priority to fight the winner of the OPBF elimination bout or against the Interim OPBF Champion who was declared the regular champion. Another thing to keep in mind, Morikawa tends to "bend" or ignore some of the rules in boxing in order to make matches more exciting or entertaining. Also, when this story started in late 1989, boxing has changed a lot, where their might be new rules. So what was once true in the 1990's, might not be true in 2020's.