Sixth grader Hikaru Shindo stumbles upon a mysterious Go board with a blood stain on it. Before he knows it he's hearing voices, one voice to be exact. The voice of an ancient Go instructor, Sai of the Fujiwara. Sai occupies a space in Hikaru's mind. Hikaru is the only one who can see, hear, or talk to Sai. Sai's one and only desire is to play Go. But he can only do that via Hikaru's body. However, Hikaru has no interest in playing Go. Will Hikaru allow Sai to play? And who is this mysterious young boy, Akira Touya?

With the recent defeat of the Meijin's son, Hikaru goes about his day normally. However, Akira is obsessing over the game he lost. He won't do anything but stare at the Go board and replay the game that he lost. When he gets word that Hikaru is at a Children's Go Tournament, he rushes there hoping to confront Hikaru and ask for a rematch.

After confronting Hikaru, Akira challenges him to a rematch. As they sit down to play, Sai notices Akira's fangs bearing down on him. Will Sai go easy on Akira, or will he crush him? And, what will happen when the Meijin challenges Hikaru to a game?

Akari invites Hikaru to the Haze Junior High festival. Hikaru reluctantly goes, but cannot find Akari anywhere. So, while walking around he stumbles upon a group of kids around a Go board. Tsutsui, the head of the Haze Junior High Go Club, is holding a competition. The prize is a book entitled "Assorted Tsumego from Touya Meijin's Matches". After seeing this Sai is eager to win it. But, can he with the sudden appearance of the Shougi captain, Kaga?

After loosing the game to Kaga, Hikaru is forced into joining a Jr. high school Go Club Tournament. He is to join Tsutsui and Kaga as the third member for the Haze Jr. High Go Club team for the tournament. But when Hikaru insists that he wants to play for himself, will he come out victorious?

The finals of the Third Annual Junior High Go Tournament - Kaiou Junior High V. Haze Junior High. With a score of 1-1 it is up to Hikaru to win it for Haze. Can he do it? And what will happen when Akira spots Hikaru playing?

Hikaru is now in Haze Middle School and joins the Go club. Akira Toya is now in Kaio. He pays a visit to Haze and challenges Hikaru to a match. Will Hikaru accept to play him?

Akira is too good against everyone at Kaio's Go club. The members don't take this sitting down, as three of them plan to take him down.

Akira is still loathed in the Go club, but he doesn't care. Even the club's sensei has bad feelings about him being there. How long will Akira stay in the club?

A boy named Yuki Mitani solves a challenging problem on the Haze Go club's posters. Hikaru knows they need a third member really badly, and tries to convince Yuki to join. However, he soon discovers Yuki's true strength.

The Go Sallon Yuki goes to doesn't mind giving him money for winning games, but they are tired of him cheating to get it. They hire a skilled player who pretends not to know anything about Go to teach Yuki a lesson. Unfortunately, Yuki falls for the trick and ends up betting 10,000 yen (about $90). Can Yuki manage to defeat this skilled player?

After Hikaru gets back Yuki's money, Yuki decides to join the club, but refuses to play in the tournament. Tsutsui explains how strong Kaio is and Yuki changes his mind. But will he play without cheating? Meanwhile, Akira discovers that Hikaru is the third board in the tournament and begs the club sensei to put him there. Is Akira willing to give up all his pride and his reputation, just for this one spot?

Hikaru, Tsutsui, and Yuki all manage to defeat their first round opponents. But, the next next round won't be so easy as they face of against Kaio. Hikaru is excited about facing Akira, but wishes he had more time to get stronger. However, Hikaru soon learns during the break that Akira was treated very harshly in Kaio's Go Club, but he never quit because he was chasing after Sai. Touched by the story, Hikaru informs Sai that he will play Akira instead of him.

Akira is quite tense at the fact that he is finally facing Hikaru, or rather Sai. All is going well, until Hikaru notices a point that he thinks should be played and Sai doesn't play it. Determined to find out why, Hikaru takes over and plays it. Sai reveals that the move might have worked, if Hikaru was good enough to back that move up. How will Akira handle the situation when he sees Hikaru really play?

Everyone is anxious to find out just who this mysterious user named "Sai" is. How long can Hikaru keep playing before he gets caught?

Players who have been following Sai's net matches attended the 20th International Amateur Go Tournament in Japan. A commotion occurs at the mention of Sai's name as everyone is trying to who out who he is. The commotion caught the attention of Ogata and Akira. When Akira and Sai engaged in a match over the net, the former is reminded of his first match with Hikaru. Akira discontinues the match so as not to disrupt the ongoing tournament but fixes a date for a match with Sai which happens to be on the first day of Akira's Pro exams.

Akira skipped his first match of the Pro exams in order to play the match against Sai on the net. Akira is perplexed over the identify of Sai which he thinks might be Hikaru while Ogata has his own thinking. Players all over the world are observing the match. Though Akira lost the match, he feels as though he had finally caught up with 'Hikaru'/Sai. When Akira heard from a Go cafe customer that Hikaru was sighted at an internet cafe, he races to the site thinking that he might be Sai. Hikaru denies he's Sai but gets ruffled when Akira seems to disregard him as a opponent. The episode ended with Hikaru saying 'If you keep chasing after an illusion of me, I'll pass by you eventually'.

Hikaru is slowly, but surely, getting better as evidenced when he beats Mitani in a game though with a handicap as well as Tsutsui. To play go with Sai, now that they decided not to play internet go anymore, Hikaru tries to get his gramps to buy him a go board/stones. When Hikaru beats a strong opponent at the go school, even to the astoundment of the teacher, he finally understands that one can only judge how strong others are when he's strong himself. He bumps into Kaio's first board when he's browsing a bookstore and the latter pulls him away to a match.

Kishimoto (Kaio's first board) played a match with Hikaru to find out his real strength and expressed his puzzlement as to why Akira sees Hikaru as a opponent when he's not as strong. Through Kishimoto, Hikaru realises the widening gap between Aikaru and himself and that it would be impossible to catch up with Akaru with Hikaru's current pace. All fired up, Hikaru decides to start off with enroling in the Insei program with becoming a Pro and defeating Aikra as his goal. However, he failed to realise that Inseis can't participate in Amateur tournaments. Thus, he's being forced to make a choice between being a Insei or quitting Haze Jr's Go Club.

Hikaru is torn by the decision he has to make. An unlikely saviour came in the form of Kaga who proposed that Shindou quit the club after showing them how strong he is - by playing three of them at once (Mitani, Tsutsui and Kaga). Hikaru prepares to take the Insei exam. Having bumped into Hikaru at the institute, Waya's interest is piqued by Hikaru who declared to surpass Akira and remarked to Isumi that Hikaru will most probably pass the exam.

Hikaru is losing the game in his anxiousness to win it. He freaks out when he realised that he didn't necessarily have win the game to pass as the purpose is for the examiner to gain an idea of his strength/potential. In reading the kifu, the examiner is amazed that Hikaru played the way he did during the 3-way match (with Mitani, Tsutsui & Kaga) and passed him. Hikaru unwittingly blurted out that Akira pursues him as a rival and received a cold reception from the Inseis who then see him as a threat. Waya and Isumi questioned Hikaru's validity when observing Hikaru's matches. Hikaru is shellshocked to find out that Kishimoto didn't even make it up to the upper half of the Insei class when he was an Insei and had quitted trying.

Hikaru aims to progress to the first class of the Insei program where Waya and Isumi take the top spots. Both of them wanted to pass the Pro exams quickly this year, due to various personal reasons. Ogata feels that Akira doesn't seem to have much of a fighting spirit recently and bring him to the insitute to show him that Hikaru had gotten into the Insei program. It succeeded in provoking Akira to rev up his pace. Hikaru learns of the new dan series that is to take place in The Room of Yuugen and witnessed for himself, the imposing presence/aura of the room. Meanwhile, the end of the episode marks the start of Akira's first dan match with Zama-sensei.

Although Ouza initally contemplated letting Akira win the match as a form of encouragement, he is angered by Akira's nonchalent attitude and decided to crush him completely. Akira forgot the safer strategy which could have won him the match, in order to show Hikaru his play. While the first snowflakes that mark the arrival of winter fell, Sai muses on the symbolic link between Hikaru and Akira and likened the presence of Akira as being placed there by God to help Hikaru on his path.

HIkaru can't seem to get any better at Go, despite the fact that he plays with Sai every day. If he wants any chance to get into a tournament and face Akira, he needs to get stronger. Sai reveals the ultimate weakness of Hikaru, he's afraid of Sai, and every other opponent he faces.

With help from Sai, Hikaru overcomes his weakness and finally makes it into the A league. Back at school, Kaga and Kimihiro have already graduated to HIgh School. Now that Hikaru's in the A league, he's slowly reaching his goal of 16th. He's even able to defeat Fuku, someone who not even Waya can defeat. Waya is Hikaru's next opponent, and Waya's confident that Hikaru will lose. That is, until HIkaru accidentally blurts out what the online user Sai said to him. Can Hikaru defeat Waya and prove to Waya that he isn't Sai at the same time?

Yuuki Mitani decides to go back to the Go Club.

The top 16 in the A league all take part in the Young Lions Tournament. If Hikaru can manage to get past the first round, he'll finally get to face Akira again. Meanwhile, Isumi faces an old rival, and everyone wants Isumi to put him in his place. As Sai and Ogata monitor Hikaru's game, they become shocked when Hikaru turns a bad move into a good move. However, when the round ends, only 3 Insei will have made it to the next round.

Ogata and Kuwabara are anticipating their matches for the Honinbou title, both anxious to greet the upcoming wave of pros in the Go world. Meanwhile, a guy who has won many college titles for Go and is well-known among the Insei is planning on taking the Go test.

Ogata and Kuwabara Honinbou continue their set of matches for the Honinbou title. They are on their final match, both having won the same number of games. When Ogata plays a sealed move for the first time, will he be able to follow up his actions and defeat Kuwabara?