There really ought to be a good reason for playing this way, rather than enclosing the corner conventionally. But this enclosure is more common than one might think: certainly in conjunction with the Chinese fuseki or mini-chinese, but also when the left side has special importance.
If White plays here next, there are a number of ideas.
was played by Fujisawa Hosai. This is a special technique: but now White can push at a with quite a good feeling.