From Bulbapedia, the community-driven Pokémon encyclopedia.
One of Chiaki's very first illustrations
Suwama Chiaki (Japanese: 諏訪間千晃) is an illustrator for the Pokémon Trading Card Game. Her very first illustrations were used in the PLAY Promotional card collection, all of which were used on cards given to players upon their 4th Season Subscription into the Pokémon Players Club. The style of her illustrations often uses soft shading and light colors, which is very similar to that of Atsuko Nishida. So far, she has illustrated 101 cards for the trading card game, and is expected to do more. Most of these cards have been in the DP and DPt eras, with only a few in the EX era of the card game. For a list of cards she illustrated, go here.
Chiaki's personal website