A former boxer and current drunkard named Danpei Tange meets a drifter named Joe Yabuki and sees potential in him. Tange offers to teach Joe how to box, but Joe isn't easily convinced.

Danpei is severely hurt after trying to protect Joe from the yakuza. Joe goes to visit the head of the yakuza group to try to get reparations for Danpei.

Danpei works hard day and night to save up for Joe and his boxing gym. Meanwhile, Joe uses the slum kids to con some money out of people and he runs into a woman named Yoko Shiraki.

Joe holes up in an abandoned building after he gets caught lying to con people out of money.

Tange sends Joe a letter to teach him boxing while he's at the police hospital waiting for his fate.

Joe ends up in a juvenile classification home and is quickly put into his place after trying to be cocky against his fellow inmates and their boss Nishi.

Joe, Tange, and the kids show up to court to hear if Joe will be sent off to the juvenile training school.

Joe and Nishi spend their first night at the Toko Special Juvenile Training School and are quickly put into their places.

Joe and Nishi are sent out with the rest of the inmates to do some farmwork. Later on, Nishi comes up with a plan to help Joe escape the island, but they meet a man named Toru Rikiishi.

Joe is completely out of it after getting punched by Rikiishi. However, later on, he had a huge surprise in store for everyone.

Joe continues to practice boxing while he's alone in solitary. Danpei and the kids try to find a way into the juvenile training school when they unexpectedly run into Yoko.

Joe tells Yoko why he treats her so badly. Rikiishi tries to interfere and Yoko proposes that they settle this in a boxing match. Tange finally gets to train Joe again in person.

Joe and Rikiishi prepare for their upcoming match. After seeing just how powerful Joe's new punch is, Rikiishi devises a unique training method to counter it.

Joe and Rikiishi finally have their first match. But for some reason, Danpei tells Joe to let Rikiishi keep knocking him down. Who will be the winner in the end?

Moved by the fight between Joe and Rikiishi, the inmates also start boxing.

Tange becomes the full-time boxing coach at the juvenile training school on Nogiku Island. Joe seems to finally be interested in training more with Tange, but Tange suddenly seems distant.

Joe keeps trying to get Tange to coach him again, but Tange just keeps ignoring him and concentrates on training Aoyama. No one expected Aoyama to get into the tournament, but he then somehow defeats the rep for dorm 7, Numata.

The dormitory boxing tournament begins and everyone finds out just how Aoyama defeated Numata.

Joe and Aoyama's match finally begins, but who will come out on top?

Joe and Aoyama's match concludes and Tange reveals something to our two fighters.

Rikiishi tells Joe that they need to have their match sooner because something came up, so they have an unofficial match out in the rain.

Rikiishi leaves Toko Special Juvenile Training School and Joe feels empty inside. Meanwhile, the final match of the dorm boxing tournament is about to begin.

Following Rikiishi and Aoyama, Nishi is also going to leave the juvenile training school, leaving Joe all alone.

Joe finally leaves the juvenile training school and goes back to the slums where he's welcomed back with open arms, and Danpei has a surprise for him.

Joe finally feels like something might be changing in his life, but then he is visited by Guerilla, who's on the run from the police.

Tange goes to the Japan Boxing Association to get his gym officially recognized. Meanwhile, Joe starts working at the grocery store Nishi works at.

Tange is unable to get the license for his gym, but then, an unexpected visitor gives them an unbelievable offer.

Joe goes to see the All Japan Rookie Championship Tournament and figures out a way to get one of the members of the Boxing Association to give Tange the license he needs for his gym.

Tange is able to get the license for his gym after the stunt Joe pulled at the All Japan Rookie Championship Tournament, but he says that Joe's not ready to become a pro yet himself. However, Joe's got his own ideas.

Joe and Nishi go take the pro boxing test and Joe finds out that it's not as easy as he thought it would be.

Joe passes the B-rank exam and takes his first real step towards becoming a pro.

Nishi and Joe both have their debut matches in the pro ring.

Everyone celebrates after Joe's first victory. Noriko gets him violets but those are quickly overshadowed by the giant bouquet of roses Yoko sends him.

Ishikura watches Joe win a boxing match and decides he wants to be just like him. He then suddenly shows up to Tange's gym wanting to join, but Tange surprisingly refuses.

Nishi loses all three matches so far after becoming a pro and loses his confidence. Tange, Joe, and the kids try to find a way to build his confidence back up and Kinoko finds a surprising solution.

Joe continues winning match after match and asks Tange when he's going to go up against Wolf Kanagushi. Tange tells him they're going to take it nice and slow, but then, Otaka sends them an invitation...

Joe, Tange, and Nishi are anxious about what Wolf's secret training could be. The kids decide they'll sneak into the Asia Boxing Club to find out what Wolf's training is, but things go terribly wrong.

Joe and Wolf's match finally begins. Whose training will bring them victory?

Joe and Wolf's intense match finally comes to an end. Who will stand victorious?

Tange takes Joe, Nishi, and the rest of the neighborhood on a hot springs trip to celebrate Joe's victory, but on their way up, they find out that Wolf may have been incapacitated.

The new year has arrived and Joe finds out that Rikiishi is losing weight to become a bantamweight so he can face off with Joe.

Joe and Rikiishi continue training for their match. However, Rikiishi is starting to worry Yoko and Mikinosuke because he is going to extreme lengths to lose weight.

Tange formally accepts Shiraki Gym's match request between Rikiishi and Joe and he tells Joe about Rikiishi's brutal weight loss regimen. Meanwhile, Nishi doesn't seem to be losing any weight...

Rikiishi has his first match as a bantamweight against Pancho Leo. Who will come out on top?

Joe asks Tange and Nishi to help him improve his sway backs so he has a way to counter Rikiishi.

While Joe continues his intense training, Rikishi is equally devoted to maintaining his weight.

On the day of the match, Joe and Danpei reunite with Rikishi during the weigh-in and acknowledge his impressive weight-cutting success.

Joe realizes that Rikishi has stabilized his body after extreme weight loss.

Rikishi's uppercut grazes Joe's cheek, causing it to bleed. Alarmed, Joe moves in close during the third round, leading to an intense exchange of hooks.

Joe fortifies his guard for the first time in his professional career, but Rikishi's fierce attack knocks him down.

The fierce battle ends. Joe extends a congratulatory handshake to Rikishi, who starts to smile but collapses onto the mat.

On the day of Rikishi's funeral, Joe leaves their condolences to Danpei and Nishi and tries to distract himself by playing energetically with the children by the riverside.

Joe wanders through the town on a snowy night, carrying memories of Rikishi. To Joe, who has no family, Rikishi was an irreplaceable presence...

Three days after Joe disappeared, a ten-count gong was held at Korakuen Hall to mourn Rikishi's death. Joe watches the scene on a street-side TV.