Yudetamago is the pen name of artists Yoshinori Nakai and Takashi Shimada, who created the original hit Kinnikuman (Muscle Man). Kinnikuman was originally drawn by Shimada since he was a child. When they were in fifth grade Nakai went to Shimada’s house and read the earliest version of Kinnikuman, inspired by Manga Michi then they decided to team up as mangaka. Kinnikuman, which debuted in 1979, quickly grew into a massive slapstick wrestling epic and one of the most popular features in Japan's Weekly Shonen Jump magazine.

The origin of the pen name Yudetamago (boiled egg) was when they were thinking about a name, Shimada farted and smelled like a boiled egg.

Good friends with AKIMOTO Osamu and KURUMADA Masami.