Ai Yori Aoshi: Enishi - Miyuki
Genres: Comedy, Drama, Romance, Ecchi
Type: Special, Episodes: 1
Aired: Dec 31, 2003
Studio: J.C.Staff
Source: Manga
Rating: PG-13 - Teens 13 or older
Synopsis:
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.