Secret Cohabitation with Big Sister — A Milk Tea Bond Thicker Than Blood

Story

That day, after that stream ended—

Thanks to the support of a mysterious sponsor, the older sister is freed from financial hardship, and her younger brother has become a university student.

The two thought they had finally reclaimed their “normal life.”

But one day, an “Intimacy Gauge” suddenly appears above their heads.

It clearly shows that their relationship is no longer “normal.”

In the morning, they cook meals side by side.
At night, they snuggle on the sofa watching movies.
Their fingertips brush in casual gestures.
Before they know it, the time they spend alone together keeps growing longer.

The “fictional love” they performed in front of the streaming camera quietly and surely transforms into genuine “true feelings” in their everyday life away from the camera—

Until the day they cross that forbidden line.

A tender, slowly heating “romance simulation” life between the siblings begins now.

System

• Total H-scenes: 16 (unlocked progressively with story progress)

• All H-scenes feature 3+ stages of dynamic animation

• Cross-section view can be toggled ON/OFF

• Some scenes support real-time clothing on/off switching

• Some scenes support insertion position switching

• This work was created with Unity.
• Please always check the trial version for compatibility before purchasing.
• Content may change without notice due to bug fixes, adjustments, or version updates.

※ Some backgrounds use AI-generated materials.

Update History

• Aug 14, 2026 – Bug fixes: Added full CG unlock function; fixed story progression and event trigger issues.

• Mar 14, 2026 – Bug fixes: Fixed Christmas event not triggering; resolved some conflicting event conditions.

• Feb 15, 2026 – Bug fixes: Fixed Christmas CG not unlocking; added guidance for CG unlock conditions.

• Feb 5, 2026 – Bug fixes: Fixed event progression stop, inverted effects, affection not updating, missing translations, and other minor issues.