新人20歳のお姉ちゃんAVデビュー！！悠木倫ねーちゃん、いくらなんでもイキすぎだろ……（Shinjin Hatachi no Onee-chan AV Debut!! Yuuki Rin - Nee-chan, Ikura Nandemo Ikisugi Daro...）

Yuuki Rin is a brilliant student attending a prestigious private university.
Even from her younger brother’s perspective—mine—she’s beautiful, has a great personality, and is someone I can proudly show off without feeling embarrassed.

We often go shopping together or hang out, and we’re so close that people sometimes mistake me for her boyfriend.
But then, one day, she dropped a bombshell.

In those videos, Rin was… well, let’s just say she was very into it.
Honestly, out of all the adult films I’ve seen in the past few years, hers were easily the most… intense.

“Hey. I’m not planning to take care of that for you, so don’t go watching them and… you know.”

…And so, this is the story of a younger brother whose close older sister became an adult film actress. A tragic tale, really.

[Translated from dlsite]