The Japanese style art in Manga (comics/print) and Anime (cartoons/animation) is based on the distinctive "Large Eye" look created by Osamu Tezuka. Manga literally translates "whimsical pictures" and dates back to the late 1700's with early published picturebooks. Anime is an abbreviation of "animation" and synonymous with Japanese animation. While early Anime dates back to 1917, the current characterstic style developed in the 1960's. Both Manga and Anime have a large audience not only in Japan, but also worldwide.
It's no wonder that many artists have taken their influence and love of the Manga/Anime style and created their own unique brand of Female Muscle. While the look and style may retain some of the "whimsical pictures" origins, these women are all power.
Here is a gallery from some talented Manga/Anime female muscle artists: Bokuman, Mikazuki-Dono (Australia), Purukogi (Japan), RENtb (Japan), S20K00Y (Japan). Check out their DeviantArt pages for more great art.