it could be photography, drawing, painting, etc.
I know JB from Got7 is really into photography. He had his own exhibit a while back.
I'm not sure about anyone else tbh.
Taehyung aka V from BTS is into photography
here you can see some of his photos https://onehallyu.com/topic/526660-personal-photo-collection-by-kim-taehyung-aka-vvvante/
Into ARTS? Yes You looking for BIGBANG TOP and G-DRAGON . They both well know among popular artists and owned rare pieces of valuable art too.
Here some pics of them with popular artists.
It also said Seunghyun (TOP) comes from a family of artists but he is also related to Kim Whanki. His maternal grandfather is Kim Whanki's nephew.
TOP also curated Sotheby Hong Kong auction in 2016 with a highest rate.
You can check some of the pieces owned by GD
They both also collect Furniture pieces too