score:5
Yes, it is usual, at least in Japan. Note that even in Europe you can't book too early.
Although regular airlines such as JAL and ANA operate on a similar schedule than other international airlines (i.e., tickets go on sale about a year in advance) for international routes, low-cost airlines operate on a tighter schedule. For example, Summer 2015 tickets at Peach went on sale on 9 December 2014, so you couldn't have booked them a year in advance like on regular airlines.