Voir Yosuga no Sora: In Solitude, Where We Are Least Alone, Season 1 - Episode 6

Haruka suggests a DNA test to resolve the paternity issues surrounding Akira and Kazuha;and Kazuha agrees. Haruka informs Akira that the DNA results will be out in five days, but Akira disappears on the fifth day. Haruka finds her at the train station, where they talk until the evening. Kazuha's mother appears, and divulges the events as they unfolded many years ago. Akira then reads the DNA results,which confirm that Akira is indeed born of a different mother.