|Anime debut||Her Whereabouts|
|Japanese voice actor||Takehiro Murozono|
|English voice actor||Christopher Ayres|
Sudou is a gang member in the Clannad series.
Sudou has a short crop of grey hair and purple eyes. He usually wears tank top shirts and a necklace.
Sudoe first appears in Her Whereabouts. He climbs into Yukine Miyazawa's resource room beaten and bruised. He says that his gang lost a brawl because of him and because of this, he's going on a journey. Yukine councils Sudou, telling him that he should be able to return to his friends. Yukine prepares him a meal and he chats with her and the others that were in the room at the time (Youhei Sunohara, Tomoya Okazaki and Nagisa Furukawa) about their gang. Another gang member climbs through the window, interrupting the group and picking a fight with Sudou. The two leave for their fight as a convenience to Yukine. Before leaving, he tells Yukine that if another idiot wanders into the resource room, she should take care of them.
He later appears in his gang's hideout when Tomoya and the others bring Yu to see his sister.
In Valiant Fight, Sudou shows up to Yukine's resource room beaten and bruised again. He explains to everyone there that their rival gang believes Youhei to be Yukine's brother, Kazuto Miyazawa. When Tomoyo Sakagami appears, Sudou flees. He's later seen at his gang's hideout where they're rallying to attack the rival gang. Sudou is present when Yukine explains the deal she made with their rival gang's leader, Sasaki. He attempts to attend the battle proposed by Sasaki but passes out after eating Sanae Furukawa's bread.
The next day, everyone who was present in the fight is gathered at Kazuto's tombstone while Yukine tearingly talks about her relationship with her brother and how he died. Sasaki is repentant of his actions and to show respect he prays to Kazuto's grave. Both gangs then follow his example. Seeing everybody praying for her brother, Yukine is finally relieved of her grief.
Sudou makes a cameo appearance in episode 16 of ~After Story~ in the photo on the Christmas card sent to the Okazaki residence.