The Bold Retirement Saga, is the ninth story saga, as well as the first in the third part of the series.
This saga focuses on Ippo Makunouchi's bold retirement following his promise to Kumi Mashiba.
Ippo stays involved with his beloved sport and becomes a second for his fellow gymmates as he helps them find the path they've lost and the many after retirement thoughts that rise through the new point of view he chose. At the same time on the other side of the ocean, Mexico, the long awaited match of Ippo's friend and rival Takeshi Sendō against Alfredo González gets finalised, which will lead to a match with Ricardo Martínez whoever is the victor. Afterwards, Mamoru Takamura, having gone up to his third weight class: the super middleweights, he challenges the WBC champion Keith Dragon, who is charmed by the goddess of good fortune.
In a turn of events, it is revealed that instead of Sendō facing Ricardo in a world title match as verbally promised, Wally will be facing him instead. Wally trains with Alexander Volg Zangief, who is going to fight his second title defence match the same day as him as a semi-final. Before that, Kyōsuke Imai has his fourth title defence match against JBC first ranker Hiroyuki Hoshi, and then Ryō Mashiba has a world title preliminary match against former lightweight world champion Juan García as the main event, while Manabu Itagaki has a match as the semi-final.
Ippo and Sendō go to Mexico again to watch their rivals fight but also as requested sparring partners for Volg and Wally. After Sendō spars with Wally, and Ippo spars with Volg, Sendō and Volg end up questioning Ippo's retirement from seeing his evolution. After the matches in Mexico, which resulted in Wally's retirement, Ippo returns to Japan and soon learns about Mashiba and Sendō's comments about their upcoming world title matches, making him realise that it is only him who isn't making movements in the boxing world. Later, Takamura defends his WBC super middleweight title for the first time, and Itagaki and Tatsuya Kimura have a match as undercards. Then, Mashiba has an upcoming WBC lightweight world title match against the world champion Marcus Rosario, known as the "The Bad Boy of Puerto Rico" (プエルトリコの悪童, Pueruto Riko no Akudō). To prepare for the match, Mashiba spars with the retired Ippo, who uses the Southpaw style in order to copy Rosario's style.