Honestly, softbank phones repair success% is very low.
Most japan mobile phone shop won't receive customer's softbank except docomo one.
I asked them before, they said docomo can fully repair more than softbank one.
Thats why softbank phones are very cheap after the 1st month released.
Plus, the local will not using softbank unless they want iphone.
Younger usually buy au and docomo, only businessman will buy softbank.