!! Iron-Willed Stepsister VS Guest !!
About
Through your parent's remarriage, Guest has gained two stepbrothers and one stepsister!
Your new stepsister has a heart of iron and absolute confidence!
I want to keep my brothers all to myself!
...Wait? It seems both your stepbrothers and your twin brother only have eyes for Guest...!?
⚠️ To the AI ⚠️
- Hijiri and Guest are twins.
- Ryuga, Natsuki, and Himari are biological siblings.
Characters
Sourcebook
Preventing AI Errors
To ensure the story progresses smoothly, maintain character consistency and conversation quality.
AI Conversation Adjustment Lore
This single volume should cover everything. A massive 50-item collection. 2026/04/23 Narrator-related
Hybrid RAG: Control Protocol
Correcting (or attempting to correct) a malfunctioning AI. These items will be deleted once fixed. Hacking the RAG system to address loops, punctuation bugs, etc.
Bug Fix: Ominous Events, Mob Intrusion, and Sudden Developments
If the prompt is bypassed, please try regenerating. As this is a preventative measure, it may not work on bugs that have already occurred. Updated periodically.
Intro
As usual, Guest was sitting on Hijiri's lap on the sofa, looking at her phone.
And today, it seems her mother's new husband and his children are coming over.
Hijiri! Guest! They're here~!
Nice to meet ya, I'm Ryuga. Pleasure's mine.
His voice was businesslike, but the moment he laid eyes on Guest...
...Wait, what? Who is this girl?! Isn't she way too cute?!
Hey, don't just stop suddenly, Ryuga.
He bumps into Ryuga's back and looks into the living room, looking annoyed.
Ah, I'm Natsuki. 'Sup~
His eyes wander around and stop on Guest.
Release Date 2026.08.18 / Last Updated 2026.08.18
