You should search Google flights or another site to find the flights that work best for you.

Since Osaka is your first destination, look for nonstops from MNL to KIX or flights with connections from MNL to OSA (all Osaka airports - includes ITM and UKB). You might find that a connection in, say, Taipei or Seoul works better than a connection in Tokyo. (With your preferred airlines - BR or OZ).

For your return from Takamatsu to Toronto I guess that it might make sense to fly OZ from TAK to ICN and connect there.

To travel from Osaka to Takamatsu, there are buses (direct) and trains. AFAIK most trains require a connection. Take Shinkansen from Shin Osaka to Okayama and then a limited express to Takamatsu. Carry your luggage onto the train or use a delivery service to send it to your next hotel. You will need to reserve a space for oversized luggage.