Japan 8D/8N Itinerary For Travelling Friends

Hello! Seeking your suggestions for Japan itinerary for 8D/8N for a group of 6 people.
We will be landing in Osaka around 9am, and will be leaving Japan via Tokyo going back in our country.
May we have suggestions on where to go places, what mode of transportation to take, and foods to try.
We are planning to visit places in Osaka, Kyoto, and Tokyo. But you are free to add other places.
Thank you in advance as your suggestions will be so valuable.

Gooday, what month, and what do you like to do?

If you are going when it is warm (later May to end September), how tolerant of heat are you?

We will be on the first week of November this year.
What we�fll gonna do there are sight seeing, eating authentic Japanese foods, and feel their culture.
We are also planning to visit some theme parks.

I'd skip the theme parks with only 8 days available to you.

I should have asked where you come from. If you want to see some awesome autumn colours, I would go to tokyo the following way - Osaka - Kyoto (everyone wants to see Kyoto but I would limit it to a day or so because it is so busy) - Takayama (in the mountains, should be full autumn colours, stay overnight) - Matsumoto (nice castle, probably stay overnight there too) - Tokyo.

From the Philippines, we will be entering Japan via Osaka.
Then we will be leaving Japan via Tokyo.

I would skip Osaka and go straight to Hiroshima/Miyajima and stay 1 night.
Then go to Kyoto for 4 nights, including 1 day trip to Nara.
Spend the rest of time in Tokyo area.
8D8N is not much time, and early November is too early for autumn colors in most places (maybe you can get lucky in Nikko area, as a day trip from Tokyo).

Based on your information so far:
Arrive KIX, go to Kyoto 3 nights. Onward to either Kanazawa or Takayama for one night. Then finish in Tokyo 3 nights. Kyoto -Takayama - Matsumoto - Tokyo has a lower cost than via Kanazawa and is quite a scenic route. If you need a theme park then either a USJ visit from Kyoto or Disney in Tokyo is probably what you are thinking of.
Adding in somewhere like Hiroshima adds a lot of cost, and unnecessary travel time when your trip is short.