Fate/Grand Order: Zettai Majuu Sensen Babylonia Episode 0

The year 2010 AD. Romani Archaman has been posted to Chaldea. There, he becomes the primary doctor for a young girl. Mash Kyrielight, Chaldea's second successful summoning experiment, is interested in the word "Senpai." The interaction between the two gives Mash a reason to hope. That hope becomes a wave and starts to spread. That is your story, the story of a normal "somebody." The story at the beginning of a journey that weaves the future.