futaba_channel
Futaba Channel (ふたば(双葉)☆ちゃんねる Futaba Channeru), translated as Double Leaf Channel or Two Leaf Channel and also abbreviated as Futaba for short, also known as 2chan, is a very popular Japanese internet imageboard dealing in otaku and underground culture.
4chan was based off of Futaba's imageboard system.
Not to be confused with 2channel, a separate text-based website.