Osaka is easy. Apartment Hotel 11 sits in Higashishinsaibashi — 5–6 min walk to the Glico Sign / Dotonbori, 3 min to the Shinsaibashi arcade, 7 min to Amerikamura. You’ll use the metro less here than anywhere else. Closest stations: Nagahoribashi (Sakaisuji/Nagahori-Tsurumi-ryokuchi lines) and Shinsaibashi (Midosuji).
Pro tip: Osaka is the most walkable city of the three for your itinerary. Dotonbori, Shinsaibashi, Amerikamura, and Namba are all within a 10-15 min walk of each other and your hotel. Save the metro for Osaka Castle, Shinsekai, and the airport.