Fate/Grand Order -絶対魔獣戦線バビロニア- Initium Iter

あらすじ

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.

(Source: Crunchyroll)

Note: This episode aired on August 3, 2019 at Fate/Grand Order Fes. 2019: Chaldea Park. It was available for download on the Fate/Grand Order mobile app, from August 4, 2019 to August 11, 2019.