Bringing wine to japan

Hi! I'd like to bring a bottle of wine for a friend in Osaka.
I've been told I can buy it in the airport (Madrid) and take them with me in the plane as hang baggae. But..I'm making connection in Dubai, so I don't know If there would be problems passing through security for the second time...

This doesn't have anything to do with the Japanese end. It depends on whether there is a security check in Dubai before you board the second flight. Your travel agent or airport staff in Dubai or even Spain will be able to give you the most accurate answer.

My feeling is no, you will not be able to take a bottle of wine with you when changing from one flight to the other, but it depends on the set-up in Dubai, i.e. whether you have to pass through security again or not.

I suggest to buy at a local supermarket, which is cheaper than DFS & put in the checked luggage. You can bring in up to 3 bottles (standard 760ml bottle) to Japan. You may be forced to pay a high cost packing service as a checked baggage, if there is one nearby the security, costing a lot more than the wine itself.

We bring Australian wine into Japan in our checked luggage (we make sure it is within the duty free limit).
We can by polystyrene packaging specifically for wine bottles at our wine merchants: very helpful to avoid bottles breaking. See if similar packaging exists in Spain

According to one Japanese government website, the duty on wine is 70yen per liter, which is less than a dollar. Are there any other charges?

Alcohol in Japan is cheap companred to many countries. A bottle of early times, 750ml is usually around 1100-1300 yen. A 750ml bottle of jack daniels is around 2000yen. The cheapest wine is 300-400 yen.

If you do try to find some nice wine that normally would cost around $25 back home, expet to pay around double, and around 4x if your purchase it in a wine bar/restaurant.

Yes, there's really no reason to limit yourself to the duty-free limit - just pay the small duty on the excess bottles, and you'll still be saving money.