With our limited time here, we spent our first day at Osaka castle, a castle that had been rebuilt after destruction by Tokugawa's soldiers and from being burnt down by lightning. The castle now has a lift inside it which makes travelling up and down the castle much easier for elderly visitors.
The sister and I climbed up the castle and inhaled as much as possible on our way down - this meant taking the time to read every bit of history plastered across every corner of each floor. Be sure not to miss the bird's eye view of Osaka should weather permits.
Another attraction that you may want to locate would be Kuromon market, a great place to grab breakfast or lunch. Not as crowded as Tsukiji market in Tokyo or Nishiki market in Kyoto which made it a lot more easier to breeze around.
Just like any other Japanese market, fresh, ready to eat seafood meals are served at most seafood shops. The sister paused for a little tuna belly treat after casting her eyes on a fellow deftly making incisions on a large tuna fish.
One of Osaka's most popular tourist destinations would be a stroll along Dotonburi aka the city's food junction. Almost like a suburb on its own, there are so many food options to choose from and surely, something for every character. Do be warned that most of the restaurants can get extremely crowded and so, would be worthwhile to spare yourself an extra 20 minutes at least if you want to dine at a highly sought after establishment.