One thing I really like about ANA is that you can preselect your seat on their website at no extra charge from the time of booking so on long haul trips it's often possible to ensure you've got an exit row seat.
That's a great feature of ANA's booking system.
But, strangely, when I booked this flight (it was close to last minute) it was showing almost every seat as full whereas when the doors were closed the economy cabin was probably 25% empty, including some of the prized exit and bulkhead row seats. Either a lot of passengers did not turn up, or a lot of seats were kept from the booking engine for some reason.
I also noticed that on each leg of the journey the window seats in the exit rows were occupied by tour group leaders, whose passengers were seated elsewhere in the plane, which makes me think that those seats are held back for such passengers.