Endou was described as an "otaku" by Reika Nishimura
Endou had wavy/curly hair and "coke-bottle" glasses.
At the beginning of the chapter, he was shown bothering Motoki about Reika, with the latter looking embarassed. He notices a strange man standing in front of the game center. When Motoki believes that Mamoru is the man his dad introduced him to so that he could work at the game center as a part-time employee, he tells Endou to go on ahead. The evil Mamoru uses his powers, causing him to fade and disappear. He then brainwashes Motoki, telling him that from now on, he will be his best friend Endou.
It is unknown what has ever happened to Endou, if he came back when the Dark Kingdom was defeated, or if he was gone forever.