The first appearance of Aika Village (アイカ村) was the author’s post to a thread for Animal Crossing’s dream suite codes in 2channel’s /wifi/ (game consoles’ online features/services) board. It was posted on December 12th, 2012.
It seems that Aika Village began spreading actually by twitter users sharing playing videos for the village which were posted to YouTube (Dec. 18th) or NND (Dec. 21st). In the description of the latter NND’s video, the poster already mentioned “I visited now topical village”. So, it seems Aika Village already got much popularity in the end of that December.
Both search results on NND and pixiv and Google Trend say that, here in Japan, Aika Village had been trending from that December to the next March.
In addition to this, Aika Village’s author, later called himself Garakku (ガラック), talked about the back story about the making of the Village in the interview by a Japanese game magazine Nintendo Dream published in April 2013. Here is a blog post reporting about this.
In the interview, Garakku said that Aika Village got much inspiration from Niconicori Village (にこにこり村) which was made by Shigesato Itoi, the main creator of Earthbound/Mother series, and Niconicori’s concept was similar to the room of Porky in Mother 3. Niconicori was appeared on an interview to Animal Crossing creators uploaded to his official website in April 2009.