The stepmother’s drag is my ex-girlfriend

The story tells that Mizuto Irito and Yume Ayai were boyfriend and girlfriend in junior high school, but they misunderstood each other over a trivial matter and broke up when they graduated. However, when the two entered high school, their parents remarried, and the former lovers became brother and sister. Their memories and the situation of living under the same roof made the two unable to ignore each other's every move. The original novel was written by Kaishiro Saiki and illustrated by Minaki. It was serialized on the KADOKAWA novel submission website "KAKUYOMU" in 2017 and was officially published in 2018. It has won the "3rd KAKUYOMU Online Novel Contest" romantic comedy category grand prize, "This light novel is really amazing! 2020" new work section third place and other awards.