Which cities???

Hi everyone,

I am going to Japan in a month's time, for 28 days (after a week in Korea), and need help deciding which of these cities/places to visit. [Edit: Solo traveller but hoping to make friends in hostels]

• TOKYO (a week, I'd love to properly explore and do everything in Tokyo)
• OSAKA
• NARA – day trip
• KYOTO
• KOBE – day trip
• HIROSHIMA
• NAGOYA
• YOKOHAMA
• NAGASAKI
• FUKUOKA
• NIKKO (2-3 days)
• KAMAKURA AND ENOSHIMA (2 days)
• KANAZAWA (2 days)
• HAKONE (2 days)
• OKINAWA (i'm thinking in late Oct/early Nov it might be too cold for this and beaches shut)
• SENDAI and cat island!

Any help/advice would be super appreciated as I currently have 16 places/areas to visit in 28 days and am feeling quite overwhelmed! <3