shirouko
A character from the Fate/stay night doujin series "Heaven's Failure", by Limit Break. In the series, Limit Break creates her using a fusion of the mindset of Emiya Shirou and the body of Illyasviel von Einzbern.
Effectively a genderswapped version of Emiya Shirou, though the tag refers only to Limit Break's character and not genderswapped Shirou images in general.