K: Missing Kings (2014)

Since the Island Academy Incident, silver clansmen Kuroh Yatogami and Neko have been searching for their master, Yashiro Isana, the Silver King. Their search having turned up fruitless, the two begin to give up hope, until they encounter Anna Kushina and Rikio Kamamoto, two members of the red clan HOMRA being chased by someone.