The referral community
Invitation App is a social network where people post their referral codes and collect rewards on autopilot.
hints & tips community for smartphone games
gamewith.jp is hints & tips community for smartphone games in japan.
Japan's online pinboard, inspiring the Japanese ways (beyond the Otaku way)
My wife being Japanese, I wanted to find a place where I could learn/share more about the Japanese culture, in a very practical way: how can I design a Japanese themed house, room, and bath. How can I discover new movies to watch, new artists to get inspired from, ...