The rules of the white elephant gift game are fairly simple. Everyone participating brings a gift, which is often something they don't want or is just a bit of a joke item. Once the game starts, the first person selects a gift and unwraps it. Then the next person can either steal that gift or pick a new one from the remaining pile. If a gift is stolen, the person it was stolen from can then choose another gift from the pile. This continues until all the gifts have been distributed. It's a game full of surprises and laughter.
The story often involves a gift or possession that is burdensome or difficult to get rid of. It might be something expensive or impractical that no one really wants.
I'm afraid I can't tell you the author of 'the last green valley novel'. It could be a relatively unknown author or a new release that hasn't gained wide - spread recognition yet. You may need to do some research, like checking with literary agents or book clubs that focus on new or niche literature.
I'm not sure specifically as I haven't read it in detail. But generally, it might be about a valley that has some sort of unique significance, perhaps related to nature, the environment, or the people living there.