APA hotels is a Japanese hotel chain which runs 556 hotels(including partner hotels. May 2020) throughout Japan. They do not operate hotels in all 47 prefectures in Japan but prefectures which do not have they own hotels are located with parther hotels. Total number of rooms including partner hotels is 81042(May 2020).
The hotels are located at downtown areas of large cities and regional cities. However, it is relatively not located in front of Shinkansen stations but walking distance from the stations. The rooms are relative small but the beds are bigger than other hotels.
APA is considers as between business hotel and city hotel in Japan. Business hotel is a category of hotel which guests are mostly staying due to business trips. Therefore there are more single rooms than twin rooms. Then, usually there is no restaurants open for lunch/dinner. On the other hand, city hotel has mostly twin rooms than single rooms. Then, there are at least one restaurant open for lunch/dinner. APA has plenty of twin rooms but do not have restuarants open for lunch/dinner.
Then, they have there own reservation system which can be more cheaper when booked directly.