|Concept art of Shuuseki Ijuin|
Except for Mega Man Battle Network Official Complete Works, where his Japanese name is kept, Shuuseki's name was not shown in any official English sources. However, one can assume that Shuseki and Chaud share the same family name in English; thus he is unofficially known as Shuseki Chaud in the games and Shuseki Blaze in the anime.
He is a very cold and strict man, especially when it comes to his son Chaud, whom he expects nothing less than complete perfection from. He expects Chaud to be continually training, and that doing anything else is a waste of time. It is even insinuated he does not let his son eat with him at dinner.
Shuuseki first appears in Mega Man Battle Network 3. His company is the sponsor of the N1 Grand Prix. Before the competition, Chaud talks with his father and hopes that he will watch him, but Shuuseki simply berates him for wasting his time.
Later on, however, Shuuseki is kidnapped and held hostage by Sunayama, who uses him as a bargaining chip when he's unable to beat Chaud in the tournament. He forces Chaud to trade his PET for his father's freedom, but with Lan's intervention he's able to save his father.
Shuuseki finally appears at the end, after Lan and his friends have thwarted WWW. Although he still maintains his icy demeanor, he seems to open up a little more to his son, despite Chaud admitting that Lan did most of the work.
Shuuseki appears in the game.
Shuuseki appeared in a flashback in episode 49 of MegaMan NT Warrior Axess. When a young Chaud starts crying in front of his mother's grave, Shuuseki says that one day he will be the head of IPC, and no matter how painful the loss is, he must avoid crying. Shuuseki also informs Chaud that he will start a Net Battle training, and he prepared a NetNavi called ProtoMan.EXE for him. A young Shuuseki also appeared in episode 32 of Rockman.EXE Stream.
- Shuuseki literally means "excellent stone" in Japanese.