"Three years ago, he had the same posture. Three years ago, he had stood behind Miyuki. Yes.... Compared to three years ago, it had changed."
Set 3 years prior to the present time, Tsuioku-hen tells the events that would change Miyuki's world drastically, as well as the events that led Tatsuya to become what he is now.
(Source: MangaHere)
