Meaning of “NuiKatsu(ぬい活)”

“NuiKatsu(ぬい活)” is an abstraction for “Nuigurumi Katsudou(ぬいぐるみ活動)”, I think.
“Nuigurumi(ぬいぐるみ)” means a plush toy, and “Katsudou(活動)” means activity.
It means enjoying various activities with a own oshi(推し) plush toy.
The plush toy is often of a oshi(推し) character or idol.
People enjoy things like traveling with it, going to cafes, or taking photos.
If you search for “ぬい活” on social media, you’ll probably find lots of photos.

Example Conversation

A: That outfit on your Nui(ぬい) is so cute! Did you make it yourself?
B: Nope, I bought it at Suriko(スリコ).
A: Oh wow, they really get NuiKatsuMin(ぬい活民)!
A: ぬいの、この服かわいいね。作ったの？
B: スリコで買った！かわいいでしょ！
A: おー、さすがスリコ。ぬい活民のことわかってるね！

*Suriko(スリコ) is an abstraction 3COINS(スリーコインズ) witch is a 300-yen shop in Japan. (Though they do sell many items priced above 300 yen as well.)
*NuiKatsuMin(ぬい活民) means people who are doing “NuiKatsu(ぬい活)”. Meaning of “Min(民) is here.