What is a fanlisting?
A fanlisting is just that. A list of fans of a particular subject. This one is for Uresei Yatsura's Lum. So anyone who is a fan of Lum would be advised to join.
Lum is the main character in Uresei Yatsura, one of Rumiko Takahashi's earlier works. Uresei Yatsura is about an unlucky (and leacherous) boy named Ataru. One day when aliens invade Earth he is choosen to try to represent Earth in a race. In this race Ataru must catch the horns of the lovely oni princess Lum. Ataru's girlfriend promises him if he catches her horns and saves Earth she will marry him. So in the middle of the race Ataru shouts out "I will marry her!". Of course he meant his girlfriend but Lum thought he meant he and became smiten with him from that day on. For more information on Lum visit this great website.
Why Yatsura Japan?
I picked the name Yatsura Japan because of the name Uresei Yatsura. Uresei Yatsura roughly translates to those obnoctus aliens. Since Yatsura is Japanese slang for alien and the story is set in Japan I came up with Yatsura Japan or Alien Japan.