On August 2021, Majimena-san decided to delete all her SetsunaYuu artworks from Twitter. While most of these images could be found on her Pixiv account (some of them even having subtle differences compared to their Twitter counterparts), she deleted them on June 2022. However, I managed to save almost all of her Nijigasaki artworks.
Lastly, the NSFW images were censored by the artist. I don't know if an uncensored version ever existed or if they were published somewhere else.
From newest to oldest. 1 - 380: Twitter 381: Twipla 382 - 457: Pixiv
@noon0012 Although I don't recall if the artist mentioned the reason, I suspect it was backlash for those who didn't like that particular pairing (since she also made her Twitter account private prior to the first? deletion). That would explain why she doesn't allow any comments on tweets with SetsunaYuu. Other shippings, like Aipomu and Yuupomu, have no such restriction.