|Manga Debut||Chapter 1|
|Anime Debut||Episode 1|
|Voiced by||Chika Anzai|
Koyuki is a high schooler, who lost her brother after saving her from an accident.
After losing her brother, she was filled with guilt and searched for a Horologue. She later found out that Horologues were actually devouring time from humans. She stopped herself after discovered the truth from Kiri and Viktor. Moreover, she realized that she didn't lose her memories: the days she spent with her brother which she considered as the most precious treasure.
- She is the main character in the one-shot.
- In the one-shot, however, she didn't lose her brother. Instead, she saved a young boy from an incident. As a result, she was injured and couldn't dance anymore with her friends. She could only watch them from afar. This regret resulted in her searching for a Horologue to revert time.
- In the anime, when she went to the graveyard, his brother name is shown to be Ralp Taj Honda.