Tasking Master Ishikawa with a smith project, the dialogue makes it seem as if you need to come back the next day the shop is open (so, if you ask him to do a service on a Saturday, you'd have to return on Monday) but opening a new dialogue with him, even if you've just closed the dialogue box, grants you your crafted items.

Confirmed v 0.8.2.600

I've experienced this as well.