Bluer Than Indigo: Fate - Miyuki
藍より青し～縁～ Miyuki · 2003
Sub & DubHDCOMPLETED
Ai yori Aoshi: Enishi - Miyuki is a 16 minute Christmas special set before the beginning of the first season.
Based on manga chapters 43-44 and would also fit as episode 21.5 of the first season.