Fujiwara no Sai (藤原佐為, Fujiwarano Sai) is the spirit of a deceased Go prodigy from the Heian period. He first resided in Honinbou Shuusaku's body and played through him, giving him fame, then later in Hikaru Shindou's. He's one of those who are the closest to playing a Hand of God.
Sai's spirit is represented as a tall man with very long, black-purple hair tied with a red ribbon, and purple eyes. He wears usual Japanese clothes from Heian period, consisting of a hat, red-purple kimono and white robe on it. He has red earring in his ears. The fan he carries seems to be a maiougi, or Japanese dance fan.
Sai looks to be in his mid to late twenties.
Sai is an extremely emotional person, who often acts childish and has great mood swings. While playing a game, Sai's behavior changes completely as he controls himself and his emotions to play to the best of his ability. There are some times, though, when he can be quite cheerful when it is not a serious game.
While being first-rate in skill, he doesn't treat others badly as if they were beneath him, even when they can not hear his praise towards them. His feelings towards Go are nothing short of obsessive.
He was born at some time during the Heian Period (794 AD through 1185 AD) in Japan.
Though little is known about his childhood, it is inferred that Sai was a prodigy at Go and eventually obtained the seat in the Royal Court, being one of two Go Instructors to the Emperor at that time.
Nearing the end of his short life, the other instructor decided there should only be one teacher, challenging Sai to a game which decided who would keep their position. Both players were evenly matched, and in the midst of playing, Sai noticed that his opponent had cheated by placing an extra stone in his captured pile. Sai was nearly about to point out the cheating but the other player pushed the same claim on Sai, who now was being wrongly accused of cheating. After both instructors were told to continue on by the Emperor himself, Sai lost due to not playing with a clear mind after being accused and the other player having the advantage, and therefore was banished from the capital with his reputation tarnished. Filled with despair, he committed suicide by drowning himself in a nearby river two days later after he left.
Unable to find peace, his soul was trapped within a Goban.
Hundreds years later, as the ghost, he met Kuwabara Torajirou, after Sai was released from the board. It is said that Torajirou was already a fine Go player, and after seeing Sai's genius, Kuwabara became a medium and let Sai play Go in his place. He quickly made Torajirou a one of the top players and achieved the Honinbou Title. However, Torajirou ended up dying young at age 33 due to helping the sick in the cholera epidemic in 1862; Sai was confined in the old Goban again as a bloodstain (which was from the then ill Torajirou).
Being sealed in the board once again, he waited well over a hundred years until Hikaru found Torajirou's Goban in his grandfathers shed.
Sai is first seen—or rather, heard—when Hikaru touches his grandfather's 'cursed goban'. His appearance gives Hikaru a shock, causing him to fall down and faint to Akari's surprise. He initially seems to be a serious and effeminate person, an impression soon proven wrong: during a history test that Hikaru has to sit through, Sai continuously fails to stop himself from calling out.
After explaing while he was trapped in the board Sai reveals his desire to achieve the Hand of God. When Hikaru tells Sai his desire to not play Go, Sai's intense feelings of sadness overwhelm him, causing Hikaru to run off, vomiting. After another few "vomits", Hikaru reluctantly agrees to play Go.
After school, Hikaru travels to a Go Salon, where other people who want to play hang out. There they met Akira Touya for the first time, a prodigy at Go though it was not known at the time, and played a game. Though technically losing, Akira can tell that Hikaru's strength (who was actually Sai) was beyond anything he had ever seen from someone in the 6th grade, a strength only found in the top player in Japan, Akira's father, Touya Meijin.
It is with this event that Hikaru begins down the path of Go with Sai on his side.
Sai's Go is complicated and on a very high level. His style of playing is quite old-fashioned, playing the same as during Honinbou Shuusaku's era, his already staggering strength only becoming stronger after learning modern Go. It has been said many times that Sai's ability to read in a game is well beyond what is normal even in pro standards.
Being one of the closest people to the 'Hand of God', Sai has the skill to not only completely overwhelm most pro players, but to sometimes win an already considered lost game.
After having over a lifetime of experience, one could say that he is one of the best go players of all time
- Because of his feminine features, long hair and his extremely emotional behavior, Sai is often mistaken for a female. These characteristics would actually be regarded as signs of intelligence and wisdom during his time.
- There is a rumor that the reason why Sai's lips are purplish blue are due to the nature of his suicide.