The most famous arc related to your description involves (the character associated with "Kei" or "Amanojaku") and Reimu's financial ruin. - - New - - Gay Japan - -bravo-- Athletes Japan 05 - Japan 05- - - 1of2 -brv78- -1 976 131 47
Here is a guide to understanding and finding this specific series. The series you are looking for is not officially titled "Final Kei Kei Kei Loan Free." That phrase is a meme title derived from the plot points. The actual doujinshi series is created by the artist circle Kiki Kiki (or Kiki) . Onlyfans - Abigaiil Morris- Jax Slayher Here
The phrase "Reimu gets brainwashed final kei kei kei loan free" refers to a very specific and infamous meme within the Touhou community. It is associated with a storyline where Reimu Hakurei falls into debt and suffers various humiliating fates.