Tokyo return fly or Osaka

Halo,
i am planning a 12 days travel to japan and i was thinking of either taking return tickets to and from Tokyo and take the bullet train from Kyoto at the end of my holidays to Tokyo to take my flight or..
Arrive at Tokyo and then fly from Osaka.
Which is best for time and money you think?

On our first trip we flew in to Tokyo and home from Osaka as the air fares were the same and it saved us the time (and money) of the longer train trip. In our itinerary we stayed in Osaka last.

On our second trip we flew in to Tokyo and out from Fukuoka, but we weren't going straight home.

I would go try departing through a different airport so that you dont have to loop back, although we have found a few nice towns near Tokyo so that we dont have to stay there the last night, eg Hakone, Kamakura, Karuizawa.

If you want to get to Osaka in a hurry, flying can make sense, especially if you are going through Haneda and don't need to switch from Narita to Haneda. But it can be an extremely long trip flying around the world though, and adding even more on to that can be grueling. There are cheap fares though such as JAL's Explorer Fare now for about 7700 per person one way, if not adding a connecting flight on to your international ticket.
If you can fly open jaw, then so much the better. But you do have to look at the airfares and schedules.

Thanks everyone for your answers.
Problem is that to fly to tokyo there are many options from athens and it takes more or less only 15 to 17 hours.
From osaka it takes 30-40 hours and i have not found something with shorter stop overs in singapoure or doha etc etc… and crazy hours staying in the airport waiting.
Also the price so far would be 50% more..
I will keep looking i guess

I'm planning to do the reverse of your itinerary. Flying into Osaka & Back from Tokyo. Try looking at flights that have a transfer in Tokyo, that should open up some options. Alternatively look at a domestic flight from Osaka to Tokyo on one of the budget carriers. Make sure to check the luggage restrictions on the budget carriers.

Here are the results of a google flights search for a Osaka >Tokyo flight on a random day

shorturl.at/kCHZ6

I've not used that link shortener before but Bitly want you to sign up now,

Scoot would be a cheap option but it would mean overnighting and an early start. Or break it up and spend a day in Singapore?