Hōzuki-san Chi no Aneki is a brother-sister romantic comedy that follows the daily life of Gorō Hōzuki, a high school boy with an older sister named Haru who is unrelated by blood. Gorō is mortified when the self-centered and lustful Haru plays pranks on him. Gorou Hazuki has a small crush on his sister Haru, but can't bring himself to admit it. However, Haru suspects this, and uses this knowledge to tease and humiliate him mercilessly. Strangely enough, this is not the start of a hentai story, but a comedy with slice-of-life elements.