All route choices, version comparisons, affection mechanics, and unlock prerequisites documented in this guide were compiled from the following community walkthroughs and reference databases.

Walkthrough & Reference Sources

Source Information Referenced
ゴリラwiki (gorillawiki.jp) Brighter than dawning blue route choice charts for Sayaka, Midori, Estel, and Mia, plus Helper Navigation notes.
巫 -KANNAGI- (kannagi35.com) Route unlock order, Natsuki June choices, and July 9 differential CG branches.
誠也の部屋 (seiya-saiga.com) Feena True Route unlock verification, May 5-24 branching, and gallery completion checks.
kappaer.net Early May RPS choices and June 11-21 Natsuki/Mia branching verification.
Japanese Walkthrough Archives (fc2.com, sakura.ne.jp, client.jp) Feena, Mai, Natsuki, and Wreathlit date-by-date choice tables, Bad End affection thresholds, and bonus scenario unlock conditions.
Wikipedia / VNDB Community Documentation Platform release history (PC 2005, PS2 2006, PC Backport 2009, PSP 2010) and English character/setting naming conventions.