Transported to another world with my friends

I opened my eye, and what came into view was a clear blue sky surrounded by green trees. I slowly raised my body with the support of my left hand while my right hand was holding my head. My vision is burly looks like I was sleeping for quite a while.
"ieee..."
My head hurts a little. Soon after, when my headache subdue my vision also became a little clear.
I saw some familiar faces lying around me.