Developer: An empty box with a common name, Opnas
Publisher: An empty box with a common name, Opnas
Release date: Dec/23/2025
Version: Final
Language: English, Japanese, Chinese (Official)
Censored: Yes (Mosaics)

Get closer to your sister, whose love for her brother is leaking out!
Enjoy intimate communication, get her in the mood, and let the moment take over as you both melt into each other.

* English is supported via machine translation. We highly recommend checking the translation quality in the demo version before purchasing.

Game Flow
My Sister Intimate Sim [An empty box with a common name]
Chapter 1:
Start with some sweet talk and light skinship with your sister, who comes home and settles right between your knees!

Chapter 2:
Once she’s completely in the mood, ask her for some "mouth play."
Don’t just let her do all the work -- make sure to show her the same love and care with your own mouth and hands!

Chapter 3:
Keep being "intimate" as much as you want until you're both satisfied, letting your desires lead the way!

Her Natural Reactions are Amazing!!
My Sister Intimate Sim [An empty box with a common name]
Your touch matters, from the type to the intensity.
Her reactions flow seamlessly.
Not only her expressions and movements, but even the conversation changes dynamically based on her state!

For Example...
My Sister Intimate Sim [An empty box with a common name]
Chap. 2:
Watch her try to stay unfazed and act cool during your light caresses!

My Sister Intimate Sim [An empty box with a common name]
Chap. 2:
With intense teasing, she becomes helpless and trembles, lost in overwhelming pleasure.

My Sister Intimate Sim [An empty box with a common name]
Chap. 3:
Enjoy deep, lingering conversations while slowly kneading and savoring the moment with her.

My Sister Intimate Sim [An empty box with a common name]
Chap. 3:
Hear her lose her composure and gasp for breath during a passionate rhythm and nipple play.

Specific Conditions Trigger Unique Dialogue and Actions
My Sister Intimate Sim [An empty box with a common name]
...And more!
There are over 50 dialogue variations throughout the game that change based on her state.
We hope you take your time to explore every facet of her reactions.

Features & Specs
- Chapter 1: Introduction & Skinship
- Chapter 2: Sixty-Nine
- Chapter 3: Full Intimacy
The game consists of these 3 main scenes.
Each scene is about 10 minutes long, with a total playtime of approximately 30 minutes.

The entire game features cute, fluid hand-drawn animations.
Please check the demo or the promotional video to see them in action!

Please use the demo version to ensure the game runs on your system before purchasing.
Surprisingly, Chapter 1 is fully playable in the demo!
(Save data can be carried over to the full version.)