Kaoru Kishimoto

The plot of Hikaru no Go revolves around the Japanese Go world. Several of the manga's prominent characters hold Go titles. The title holder is then called by a combination of their name and the title they hold. In the case of a multiple title holder the most prestigious title they hold is used. The 7 major titles mentioned are Kisei, Meijin, Honinbō, Jūdan, Tengen, Ōza, and Gosei.

Hikaru is the Main Protagonist of Hikaru no Go and a sixth grader in elementary school. An important factor in the development of Hikaru's passion for Go is an encounter early on in which Hikaru becomes the rival of Go prodigy Akira Toya. At first, he thinks that Go is just for old folks and he is annoyed at Sai's demand to play, but little by little his passion for Go increases as he plays more and more. From being a member of a school Go club to becoming an Insei and finally a professional Go player (at 14 years old) a year after Akira, Hikaru matures throughout the course of the series. Throughout the series, Hikaru gets older in age as the series follow him from 6th grade to high school. Hikaru is often portrayed wearing clothing having the numeral "5". This is a pun on the Japanese word for five: 五, which is pronounced go. Part of his strength is his ability to read far into the game very fast, and to make seemingly stupid moves, which, in fact, lure the opponent to playing what looks like the obviously correct move, which Hikaru then uses against them.

Voiced by: Tomoko Kawakami (Japanese); Samuel Vincent (English)

A spirit from the Heian era of Japan and mentor of Hikaru Shindo. Once the Go instructor to the Emperor, Sai continually plays Go, his goal being to one day play the divine move. Sai's ghost had previously possessed the real-life figure Honinbo Shusaku who became a renowned Go player. Sai holds a rivalry towards Koyo Toya and through Hikaru persuades Koyo to have a game with him; with his wish realized when they play a game through the Internet. After the legendary match that ends with Sai's triumph by the narrowest margin (a ½ point), Hikaru discovers another move which would have turned the game around. Witnessing Hikaru's maturity, Sai comes to feel that his one-thousand-year time in the world is going to end without his fulfilling his wish of obtaining the divine move; but he reasons that perhaps he was fated to awaken and teach Hikaru, who might obtain it in the future. A few days after the game with Koyo, Sai suddenly disappears as he feared he would. Hikaru was dozing during their last game, so he could neither terminate his last match with Hikaru nor say goodbye to him. Sai is gone, leaving Hikaru depressed and wanting to quit the game. When Hikaru plays Isumi, Hikaru realizes that he will continue to play Go, for Sai lives on in Hikaru's Go. Extremely effeminate by today's standards, Sai is often drawn with traditionally feminine features and mannerisms. Yumi Hotta has joked about fans mistakenly calling him a "she" in the "intermission" pages of the manga. Sai's extremely emotional behavior is also proper for a Heian male; he sometimes cries copiously in chibi style, soaking his long sleeves with tears, which in his own time would be respected as a sign of intelligence and sensitivity. His name Fujiwara suggests that he is related to a noble family of extremely high prestige in the Heian period, the Fujiwara clan. Sai has a high sense of honor, abhorring cheating and bullying. Voiced by: Susumu Chiba (Japanese); Brad Swaile (English)

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