Kim did plan a "Lunar Shadow Reverse" where Shinica dreamed the events of LS.
Just with Serenity switching places with her, and Shinica not knowing what's going on (it takes place just a day prior to LS, I think?) and stuff.
Probably not canon...
Perhaps Kim could add Reverse Mode to Lunar Shadow. In that mode, the game world is mirrored, the difficulty is increased (with level layouts altered) and you play as Shincia. Also, there's a new final boss at the very end...