There's something about this that doesn't sit quite right with me. On paper it might be a good idea, but I can see a lot of potential for it to turn into a jumbled mess like that danbooru thing. The ideal of small groups of friends grouping around boards with specific subjects could lead to a multitude of tiny closed-off communities/cliques, eventually each with its own duplicate set of general interest sub-boards, meaning less chance for growth of a snowballing overarching culture a la 2ch/futaba. With this plus the option of hidden boards, you're leaving yourself open to lots of bad stuff like racism and cp. It also seems to have stopped working all of a sudden.

If wakachan links to it the links would probably be to individual boards instead of the site as a whole.