Japanese efficiency and really decent cost! Flew RT Narita-Sapporo Sept 2014 and loved it. English website that was understandable. Every employee super nice and since I was the only non-Japanese on the flight, did all the announcements in English as well as Japanese. No Frills and they mean it.
Fly on workdays: As many passengers prefer to fly on week-ends, week-end tickets sell first. If you don't book your trip well in advance (2-3 months beforehand) you may notice, for example, that Thursday flights are cheaper than Sunday flights. Some low cost carriers have special promotions on the flights during the week.