From Bulbapedia, the community-driven Pokémon encyclopedia.
Kagemaru Himeno (Japanese: 姫野かげまる), born July 24, 1972, Kanagawa Prefecture, is a writer and illustrator who has provided material for Pokémon since the early years of the franchise. She started doing manga illustrations for RIBON Original in 1994, a magazine published by Shueisha, who along with other publishers Hakusensh and Shogakukan, own VIZ Media, which publishes manga outside Japan. Since 1997, Himeno has done many illustrations for Pokémon-related publications, including Pokémon Tales and her own series How I Became a Pokémon Card. She is also one of the few illustrators that has continued to produce card art since the early years of the Pokémon Trading Card Game. She likes to go by the nickname "Himemaru" (ヒメマル).
Work for the TCG
Himeno's artwork has been featured on cards since the Jungle expansion, and as such, it is usually instantly recognizable to long-time followers of the TCG. She openly admits that she loves the paintings she does, which reflects in the quality of her art. Himeno uses watercolors and often uses bright and vivid colors with softer tones to highlight areas of light and shadow. She also adds soft white flecks on some her images, which could be interpreted as cotton spores or the like. These are particularly apparent on her older works. Over the years, she has developed a sharper eye for detail, resulting in more crisp images with more adventurous backgrounds. For a list of cards she has illustrated, go here.
Himeno's personal blog