FullAni is a fully animated mahjong game, developed and published by Leaf, which was released in Japan in 2006.

The main character, Isamu Morozumi, is playing an online game in his room. A heavy direct hit lightning strikes the entire building. The monitor in the room glows strangely white, and the electric shock emitted from the screen envelops the childhood friend Rinko and the protagonist. When he noticed, the protagonists were in a strange world.