Yo Pinoy,
My family visited Osaka-Hakone-Tokyo last Nov and it was the most memorable trip we had. But to enjoy it, you need to stay warm and comfortable.
Basic Cold weather wear such as:
1st Layer: Thermal Wear (or T-shirt <- I wore this)
2nd Layer: Sweater
3rd Layer: Jacket that can handle down to 4 Degree Celsius (Might not be sufficient at Mt Fuji 5th Station) or Down Jacket
but most people would have got that right and missed out on the more important things:
1) Protect your hands - Get a good quality Thermal Gloves (I was shivering with my D90 on Mt Fuji, those cotton/wool gloves cannot make it).
2) Protect your Neck - Get a good quality Thermal Scarf (Can cover neck, mouth and cheek when in the open or when windy)
3) Protect your Ear and Head - Get a Thermal Beanie that can cover your ears too (actually more of your ear, it's one of the earliest to feel the pain)
4) For the unforeseen position that may feel too cold - Get Heat Packs.
Now you can really enjoy your holiday