You'd think they'd all be miserable and she'd be torturing them... but no. Hilariously enough, they're probably doing something more worthwhile than just lazing around and they have Yuuka to thank. From what I see, Satori and Komeji have something to do together by planting seeds, Orin probably uses the corpses she carries to make great fertilizer, Kisume and Parsee water the plants and Okuu gets to freely train her powers in a safe way by being the sun for Yuuka's plants.
My respect for Yuuka just went up A TRILLION FOLD.