Searching for " Magical Girl Mystic Lune " yields several creative projects involving a "mystic girl" or "magical girl" named Lune, though a single definitive "save link" for a game by that exact name is not universally listed. It is possible the request refers to " Meet Lune Silverlake ," a mystic girl from the Realmners universe.
There is also a hidden 4th NPC (transfer student “Yuki”) only findable if you patrol on Day 7 evening and choose “Follow the strange light.” Yuki’s Link gives a time-freeze ability but locks you out of Reina’s route. magical girl mystic lune save link
The Transformation