I don't see what the PCV valve has to do with it. Even if it were clogged, it would not cause an oil leak, because there is a breather tube from the...
Aisin is a Toyota company and Toyota are full of their products. Just an idea: There is a good chance that Yaris parts might fit, exception the bell...
Be sure to take one for a test drive ASAP - you'll get a better idea of what these cars are all about. After my test drive, I couldn't find a reason...