Coming with My Brother!

On the twenty-fifth birthday of Nao, her younger brother disappears from their parents' home only to appear at his sister's apartment. Nao lives with her friend Saki who is wearing a short skirt. When Nao glimpses Kotaro sniffing her panties she is game for more after going through the shock and anger stages and wears her own short skirt. Saki has other ideas however. Three is a crowd apparently.