Hikaru no Go Wiki
Shinichiro Isumi
Kanji 伊角慎一郎
Rōmaji Isumi Shin'ichirō
Gender Male
Birthday April 18th, 1982
Age 17 (beginning),
19 (end)
Blood Group A
Sign Aries ♈
Occupation Go player
Affiliation Insei
Go Level 1 Dan
Rivals/Friends Yoshitaka Waya
Hikaru Shindou
Yang Hai
Le Ping
Manga Debut Game 36
Anime Debut Episode 21
Japanese Voice Actor Kenichi Suzumura
English Voice Actor Kristian Ayre

Shinichirō Isumi (伊角慎一郎, Isumi Shin'ichirō) is a friend of Hikaru and one of the oldest Insei before he quit after failing the Pro Exam for the 4th Time. However he finally passed and become 1 Dan Player after training at the Chinese Go Assocition.


Isumi anime
In the anime


Isumi is often considered too sweet and lacking in backbone, but he is generally polite and treats everyone with normal behavior and respect. There was only one instance where he talked back to someone, Ochi, who had berated him for losing three games straight.

Isumi has shown emotional problems as he is easily affected by tension and pressure. He tends to worry about many things, such as seeing Hikaru improve his skill and learning from Ochi that Akira attempted to inquire about Hikaru, which ended up causing him to make a mistake during the match against Hikaru during the pro exam. This resulted in him inadvertently moving the stone to a different place after already placing the stone on the board, greatly affecting him emotionally and causing him to resign the game out of shame, resulting in three consecutive losses.

His emotional state was one of the reasons why he wasn't able to pass the Pro exam after taking it so many times, despite being the number one Insei. However, he was able to maintain calm and control at certain times and eventually learned how to fully control his emotions during his time in China after being advised by Yang Hai.


Little is known of Isumi's history, other than he liked to play go at an early age, a common trait to most Go players. Isumi became an Insei and became one of the top Insei, however he was unable to past the Pro Exam and had failed three times.


Internet Go Arc[]

Isumi makes his first appearance where he and Asumi talk about why Akira didn't attend the first day of the Pro Exam and Isumi noted himself that he will face Akira sometime next month.

Insei Arc[]

When Hikaru joins the Insei class. Although close at first, Isumi didn't look down on Hikaru. In the Young Lion's Tournament He goes against Mashiba, an arrogant pro who taunts him for repeatedly failing the pro exams despite being the top insei. Isumi however defeats him easily.

Once Waya took a liking to Shindo and started to bring him along for training, the three boys gained a friendship between each other. Waya and Isumi decide to help Hikaru gain experience against adults to better prepare him for the final rounds. Hikaru, Waya, and Isumi form a team to play at a Go salon, in which the three have their entrance fee waived when they manage to tie a series of three games as a team. After playing and winning at another Go salon, the three go to a sushi bar to celebrate their victories.

This proved to be the start of Isumi's downfall as when he and Waya brought Hikaru to a Korean Go Salon, it was shown just how much potential he had, scaring him.

Pro Exam Arc[]

Throughout the exam, Isumi was one of two players with a winning streak until he played Hikaru. He becomes anxious after learning from Ochi that Akira is after Hikaru. Being nervous of Hikaru's strength, Isumi used nearly half the allowed time during the first half of the game and goes into overtime, something that was not usual for Isumi. During the game, Isumi's mind was so cluttered that he placed a stone on the wrong side of atari. After already taking his fingers off, he grabbed the stone again and put it where he actually wanted. This was against the rules that under normal circumstances would make the player lose the match.

Under great pressure, Isumi resigned, both boys being affected negatively by the outcome. Not being able to regain his normal game again, He suffers two more losses to Waya and Fukui. Later Isumi plays against Ochi who berates him. Isumi angrily tells him "Shut up" and soon Isumi regains his normal game and beats Ochi. As the pro exam continue Isumi soon plays against Honda who makes a wedge move. Unable to turn the tide, Isumi resigns and suffers his 4th loss. Isumi hopes that he gets a chance for a playoff if Hikaru or Waya lose their game but both Waya and Hikaru won and passed the pro exam. Isumi didn't make it to becoming pro for the fourth time and started to ask whether if he was able to succeed.

Chinese Go Association Arc[]

After dealing with that, Isumi stopped playing Go for awhile and quit be an Insei, to be alone take some.time reflect on his skills as a go player.

Sometime later, Isumi agreed to go to a goodwill tournament in China, Beijing, along with a few of his older friends who were already pros, where he played a young player by the name of Zhao Shi. Isumi, unfortunately, lost again but instead of losing hope, he decided to stay one more day to play Zhao again to prove to himself that he isn't lost. One of the head teachers at the school told Isumi that Zhao had left already for another event for three days. This didn't stop Isumi and he chose to stay until Zhao had returned. After hearing so, the instructor invited Isumi to study at the school until then, saying that he could stay at a nearby hotel. Even with the language barrier with most of the people, Isumi thinks this is good for him. The teacher showed Isumi around the school until Isumi met a young pro, Le Ping, who at first Isumi mistakes for Waya due sharing a resemblance.

The teacher asked Le Ping to play Isumi as a friendly gesture. The game goes horribly for Isumi as he underestimated Le Ping's strength and loses yet another game. He then meets Yang Hai who is one of the only players in the school who can speak Japanese and offers to let Isumi stay in his dorm room for the few days though Isumi respectively declines due to wanting to be alone. After stopping for a break and losing another game, Isumi is called by his father who asks what is going on. That is when Isumi decides that he will be staying in China for two months to train for the next Pro Exams.

Once leaving for the day to find a Hotel, Isumi goes back to Yang Hai in dorm 303, hoping the offer still stands. Yang hosts Isumi but once finding out that Isumi lost to Le Ping, he says that if Isumi is weaker than Le Ping he can't stay. Yang then tests Isumi with a game of Go where it is then known just how strong Yang is. Though not being clear, Isumi assumes that Yang thinks Isumi is worthy of staying and begins to mentor Isumi for the duration of the two months.

In the next two days Isumi plays and loses all his matches, and when finally his original opponent, Zhao Shi, returns, he tries to challenge him to another game, but Le Ping interrupts and asks to go bowling. When Zhao asks what is going on, Le Ping explains that Isumi is a weak player who is trying to train. Yang Hai overhears this mocking and begins a bet with Le Ping, saying that in one week Isumi will be stronger than Le Ping. Le only agrees if Isumi loses, Yang has to stop bugging him to study.

Later than night Yang begins to teach Isumi how to control one's emotion when playing Go. Not even considering the possibility of mastering self-control, Isumi was in awe by this revelation. During that week of training, Isumi played well, gaining compliments from the students who lived there. He even won an against one of the pros by the name of Chen Yi in a league game.

On the day that was scheduled to be the game between Le Ping and Isumi, Yang purposefully waited to get Le Ping frustrated, even strategically whispering in Isumi's ear, making Le Ping think that Yang was giving some tactic. Once figuring out the near cheating ploy, Isumi rushed to Le Ping, apologizing for the wait, and then took off 20 minutes of his game clock. Isumi then won the game by 2 1/2 points.

After the loss, Le Ping become more willing to play just to try to beat Isumi. This was actually a good thing for both players because Le Ping was threatened to be sent home because of his lack of studying.

Return Arc[]

When the two months in China was over, Isumi came back to Japan for the Exam, though wanted to play Hikaru one time before hand, to prove that he has gotten stronger. Little did he know that Hikaru had, at the time, given up in playing.

Thankfully for both Hikaru and Isumi, after pleading, Hikaru agreed to one match. Though it isn't clear who won, it didn't seem to matter because both Hikaru and Isumi gained everything back that they lost; Isumi his confidence, and Hikaru, the chance to play again without hating himself.

Later, Isumi went on to the Pro Exams and finally passed with Kadowaki and Honda. He had the record for most wins, never losing one game. Eventually, after becoming a pro, Isumi climbed up in the Go world, even beating Honinbo Kuwabara, one of the best players in Japan, with a handicap.

Hokuto Cup[]

Isumi is too old for the Hokuto Cup, but spectates the tournament with Hikaru's other pro friends.


Isumi is an above average player for his age and has time and time again proved himself to being called that. Isumi has the ability to calm himself when facing a tough move. Although not a prodigy like Akira, or unknown potential like Hikaru, Isumi is part of the wave of 'young and strong' Go players that have been popping up lately.

Initially having trouble controlling his emotions while playing hard matches, after learning for Yang Hai, Isumi greatly increased his skill. Isumi's skill will grow for he is now being allowed to go head to head with higher dan professionals.


Hikaru Shindo[]

Best friend and rival. Though being the reason why Isumi lost his chance at becoming a pro, Hikaru was also the reason why Isumi is now stronger than ever.

Yoshitaka Waya[]

Best friend and rival. When they met isn't really touched on, it is assumed the became quick friends during the first time they both entered the exam to be a pro. Isumi is stronger than Waya but still considers him as a rival.

Yang Hai[]

Friend. It is not clear if Isumi considers Yang a rival. Yang Hai was one of the few people that were nice to Isumi, which gave them a mutual relationship. Even after a time skip, during the Hokuto Cup Tournament, Isumi and Yang still appear to be close.

Le Ping[]

Friend. Le Ping considers Isumi his rival. After first mocking Isumi for being weak, then being proven wrong a week later. Le Ping has grown frustrated with Isumi's strength and challenged him over and over to games until he can dominate over Isumi.

Isumi sees Le Ping as a great player, but can't help but kinda feel like an older brother, even taking care of Le Ping when he had a stomach problem. It is not known if Le Ping still tries to beat Isumi even after he left for Japan.


  • He apparently likes denim jackets.
  • Isumi is rank first in the Second Character Popularity Poll