Gensou Mangekyou: The Memories of Phantasm
English name: Touhou Fantasy Kaleidoscope: The Memories of Phantasm
Genres: Fantasy
Type: OVA, Episodes: 18
Aired: Aug 12, 2011 to May 7, 2023
Source: Game
Rating: PG-13 - Teens 13 or older
Synopsis:
Marisa, an ordinary magician, suspects a youkai is behind the winterly weather in the middle of spring. She goes off to investigate and soon arrives in the netherworld, facing the youkai behind the strange incident. Will her friend, the shrine maiden Reimu, arrive in time to save the day or will all be lost?

(Source: AniDB)