Koikishi Purely☆Kiss THE ANIMATION

あらすじ

Seven制作のOVA。2013年夏、全2話、完結。

Based on the erotic game by Effordom Soft. Since childhood, our protagonist Kaname has always dreamed of becoming a Knight. After a near-fatal terrorist attack nearly killed both him and a new-found friend, they make a childhood promise that one day they’ll meet again in their quest to become splendid Knights that can protect others. Now, many years later, Kaname is about to enter a special school run by his father, where he and his younger sister Yuu (a big-brother-loving genius who skipped a grade to be with him) will be part of a special Knights-in training club called “Esquire”.

あらすじはAniListより（英語）。