Have you played any of the previous Okisho scenes? You wouldn't want to access it unless you've played WGB001-004 prior. There's a problem we've identified with how the route is mapping we hope to fix soon but they can be accessed via dev mode using the scene select menu. Just type in the scene number (in this case WGB005) and select start scene. Just make sure it's set to the right size or errors could occur (WGB005 is a size 2 scene).