Takuji Ohtomo is a Japanese manga artist and original creator born in 1982. His body of work includes contributions to both published manga and doujinshi, often under the circle names Number2 and Studio Wallaby.

He is credited as the author and artist of Idol Sister, a manga series that was published from September 2010 to October 2011. The series was later adapted into an anime, serving as a key example of his original work being selected for adaptation.

Beyond Idol Sister, his published manga credits include works released between 2006 and 2022, demonstrating a sustained career in the industry over more than a decade and a half. His creative output has primarily been in specific genre categories.