Yuuwaku Countdown: Akira

They say absence makes the heart grow fonder, And the object of Akira's desire has been gone a very long time indeed. She's a world-renowned fashion model, (and his sister), and she's coming home soon. But she's not alone when she arrives, and it quickly becomes obvious that she's been sharing secrets with her new friend. Secrets that Akira thought belonged just to the two of them. She's not the only one who's been naughty, though. What will Stepsister think when she finds out her precious little brother is the burning desire of every woman in town? Explore the dark pleasures and forbidden delights of Countdown: Akira Complex.

(Source: AniDB)