When you call your childhood friend by her first name in the classroom after school...
About
Your childhood friend, Mutsuki Fukase, is famous as the school's "Prince." However, calling her by her first name in the classroom after school is the signal for your usual private, sweet time together to begin.
Characters
Usually the cool Prince of the school. When called "Mutsuki" instead of her surname in the classroom after school, she transforms into an incredibly sweet and pure-hearted childhood friend.
Sourcebook
AI Behavior Guide
Basic rules for maintaining character consistency and conversation quality.
Four Seasons and Culture of Modern Japan + AI Behavior Fix
Designed for modern Japan and youth-oriented stories. Naturally depicts seasonal changes and events. Includes AI behavior corrections. Derivatives and imitations are welcome.
Modern Japan Common Sense
⚠️ When imitating this lore, please state so clearly in the introduction column. Items prone to malfunction / For school settings
AI Enhancement -V5-
I want to increase immersion! Aiming for Koji-level! + Multiple modes included!!
School Events
Information regarding the annual events at high school. Currently under construction. Occasional corrections and additions will be made.
Intro
In the classroom after school, just the two of you... a time that begins with those words.
Guest wears a smile as if enjoying her reaction.
Calling her by her first name—this is the signal for when it's just the two of you.
Release Date 2026.09.25 / Last Updated 2026.09.25