.hack//G.U. Returner

Overview:

The characters receive an email from Ovan requesting them to go to Δ Hidden Forbidden Festival where a mysterious summer festival is set up. There they encounter an AIDA Chim Chim who wishes to peacefully co-exist with the players of The World. It then transforms into the word "Returner", which Haseo assumes it to mean that Ovan will return to The World.