Hello there, I was just wondering if you guys can help me with a few details for my itinerary.
I'm planning on going to Seoul and Tokyo for 3 weeks in August 2016 (the first 3 weeks to be exact).
I'm well-aware that it's peak season, but how far in advance should I book my trip?
It should be noted that it is also my first time trying to do a multiple city round-trip booking as well: YYZ->ICN->NRT->YYZ.
Is this feasable, or is there a much better routing with cheaper alternatives?

I'm sorry if this type of question has been answered before, and if so, please direct me to any available threads.
Thank you so much!