This artwork and the two which follow are modified versions of requests from a member of pixiv. You'll have to see the original ones there.
It features "KiddyFriendlyOC" of DeviantArt's OCs Anna Lindquist and Mei-zhen Cailong doing backstrokes in a swimming pool. The Chinese symbol on Mei-zhen's tankini translates into "Destiny".
Hope you like this.