Hanamichi Sakuragi, an entering Shohoku high school freshman, holds a record for being rejected by 50 girls during middle school. His nearly 2 meters height and bright red hair causes most students to write him off as a delinquent. One day, a girl named Haruko Akagi approaches Hanamichi without any fear. When she asks Hanamichi "do you like basketball?" Hanamichi falls head over heels for the girl of his dreams. Without missing a beat, Hanamichi tells her he loves basketball, and the two head to the gymnasium where Hanamichi learns about the slam dunk. He also learns of Rukawa, one of the country's top basketball prospects, also a freshman at Shohoku.
Something appears to be wrong with Akagi; after getting knocked down by Uozumi, he started playing horribly. Kogure was forced to call a timeout in order to straighten things out.
Miuradai revealed a secret weapon of theirs that'll help them try and overcome Shohoku, and that's the ox Nato.
After Rukawa beats up those thugs, Hanamichi is shocked and asks him for his name. When he discovers that he is the one that Haruko has a crush on, he becaomes angry. Then, Haruko comes and helps Rukawa with his wounds, but he dismisses her and this makes Hanamichi very angry. Haruko mistakes Hanamichi for injuring Rukawa and she says that she hates Hanamichi. Hanamichi's world comes tumbling down again.
After being dumped by Yoko, a girl he really liked in Junior High, Sakuragi Hanamichi was devastated. On the first day of school, he was approached by a girl who asked him whether he likes basketball or not. He immediately said he loves it although he has no idea how to play the sport. His world is filled with hope again.
Sakuragi mananges to dunk over/through Akagi. Akagi is intrigued by Sakuragi's raw power, but doesn't think he's got the drive to make it on the team. Still, he ponders what the team would be like if he was to join.
Sakuragi Hanamichi has been training in the basics for two weeks under Ayako and he wants to play with the other. Akagi refused to let him play. Out of frustration, he quits the team. But after seeing Haruko's face, he changes his mind again.
Impressed by Sakuragi's raw power and general brute force, the captain of the judo club tries to recruit him away from the Basketball team.
Akagi decides to test Rukawa's skills against his own to see if Rukawa really has the talent everyone says he does.
Sakuragi declines Aota's offer of joining the Judo club. Kogure and Ayako were overjoyed at Sakuragi's refusal and Akagi was very much impressed by Sakuragi's words.
The night before their game with Ryounan, Akagi decides to try and teach Sakuragi basic defense, starting with rebounding. Learning quickly, Sakuragi impresses Akagi. After the practice session, Sakuragi encounters a scout from Ryounan, and fills him in on who the REAL star is.....
After successfully persuading Anzai to let him join the game, Sakuragi shows how much he has improved in basic skills such as dribbling. But in the game, he refuses to pass the ball to Rukawa out of jealousy.
The next day, Haruko has to accompany Sakuragi to the sports shop to buy a new pair of shoes because his old shoes are in a bad shape after the practice game with Ryonan.
Having mastered dribbling and passing, Sakuragi moves on to shooting, which is a lot harder than he had anticipated. Frustrated by his lack of skil, Sakuragi gets some extra help from an unlikely source: Haruko.
With just 8 minutes left in the second half, Ryonan is still leading. Taoka tells the Ryonan to continue to attack. Sakuragi plays whole-heartily and this impressed Sendoh.
After getting the permission to allow Sakuragi to learn the basics of shooting, Akagi asked Rukawa to demonstrate how to do lay-up shot. But Sakuragi got into a fight with Rukawa instead.
Sendoh is amazed at how good Shohoku has become, thus begins to take the game seriously. Anzai then, calls both Rukawa and Sakuragi to approach, to tell them of his plan.
Sakuragi is eager to play too, thinking of what Akagi has told him the previuos night. At Ryonan High, Anzai is greeted by Ryonan coach, Moichi Taoka. In the locker room, Anzai finally announces the starting five players who are Akagi, Yasuda, Shiozaki, Kogure and Rukawa.
Ryota Miyagi returns to basketball after beening injured in a fight. Ayako heard rumors that Miyagi was back in school, so she decided to investigate. She brings along Sakuragi and see that Miyagi is into another fight realizing that Ayako and Sakuragi are together sparking jealously into his eyes which causes a problem. Will Miyagi and Sakuragi be able to coexist...
Ryonan is leading with 3 points ahead of Shohoku, Taoka said that the game will depends on how Sakuragi plays. Meanwhile, Sakuragi begins to realize how important rebounds are.
When Hanamichi calls basketball a 'dumb game', the captain of the basketball team challenges him because Hanamichi had made fun of his favorite game of all!
A former member of the Shohoku team returns with a major axe to grind, which spells doom for the team.
Sakuragi keeps begging Anzai to let him join the game. At 14 mins, Ryonan has a 0-15 lead, with everyone cheering for Sendoh. Sendoh and Uozumi, both play briliantly. The first half ends with a score of 42-50.
Although Shohoku has lost the game, Sakuragi played very well for his first game. Sakuragi and Rukawa vowed that in their next game with Ryonan, they will beat Sendoh.
Mitsui and Tetsuo were defeated, but Mitsui still continued to fight. Though when Akagi enters, the atmosphere becomes dense. Akagi slaps Mitsui around. Kogure then informs everyone that Mitsui use to be an excellent basketball player, and was even on the team. Kogure then proceeds to tell the rise and downfall of Mitsui's basketball career.
It seems that Mitsui was once a great basketball player himself before High School. Though something happened during practice that changed his life forever.