In Osaka the neighbourhood you book effectively sets your itinerary. From Kansai Airport, the Nankai Rapi:t reaches Namba in roughly thirty-five to forty minutes, JR Haruka reaches Tennoji in about thirty, and Umeda takes around an hour. Stay in Namba or Shinsaibashi and you walk to Dotonbori, Kuromon Market and the Shinsaibashi arcade; stay in Umeda and the trains to Kyoto, Kobe and Nara are at your door.
Osaka rooms tend to be compact but close to a station. If you are moving with luggage, whether the hotel is within a five-minute walk and how many transfers you need matters more than the star rating. Properties with a natural hot-spring bath, such as the Dormy Inn group, often rate well despite small rooms, and for a fixed purpose like USJ or an early flight it can be worth booking one night nearby.
During the late-March to early-April blossoms, Golden Week, summer fireworks and November foliage, demand and rates in Namba and Umeda can rise and popular rooms may go early. Mid-January to February and the June rainy season can offer lower rates, depending on the dates.
In Japan the total can change within the same hotel depending on the plan. Before booking, check whether breakfast is included, how the public bath is used, whether accommodation and bathing taxes are paid on site, and the free-cancellation deadline. Check-in is typically 15:00 and check-out 10:00-11:00, with early check-in usually chargeable. Rooms are often smaller than Korean travellers expect, so confirm the bed configuration and whether an extra bed is possible for three or more guests.
For two nights, keeping one hotel in Namba or Shinsaibashi and walking to Dotonbori and Kuromon Market keeps transfers shortest. With three nights or more, spend the first two in Namba and move to Umeda or Shin-Osaka for the last night to add a Kyoto or Kobe day trip or a shinkansen connection. For an early-morning flight, a night near Kansai Airport is the safer option.