One lecture per week – pros/cons?

I am applying to Japanese undergraduate programs taught in English, and it feels like it's the norm that there's one or two lectures of a subject in a week. How do students even begin to learn things with that kind of schedule? That's barely anything at all. 4 hour a week for 4 credits is the norm everywhere else, and it makes complete sense.

Could someone please tell me realistically if they have learnt and retained complex subjects through this weekly teaching method? Complex subjects like Physics and Chemistry?