How to buy a locked-SIM iPhone

Hi there, I'm going to travel to Japan next month.

Can someone please help me:
- How to buy a locked-SIM iPhone (iPhone 6, 6+; activated but unused) (can use only when you have a SIM card from AU KDDI, Softbank or Docomo/ only for Japanese)
- How much is it?
- Where to buy?

I know this because some of my friends have that locked iPhone.

I'd appreciate some help.

P/s: Sorry for my bad English :(

Hi there, I'm going to travel to Japan next month.

Will you be a resident? Otherwise you won't be able to purchase a contract phone.

You can however, purchase an unlocked phone from Apple. They start around 80000 yen for an iphone 6 depending on how much space you need.

Thank you :D
I mean I'd buy an activated phone but unused from someone, not at the store :D

Yes, I think that is technically possible but it is highly irregular. May I ask why you would need to go this route as there may be better options available to you.

Because I think it's not as costly as the unlocked one :D

If it's a locked phone, you can only use one of: AU KDDI, Softbank or Docomo.

And you can't use it with an overseas SIM, when not in Japan.

You can get other phones, unlocked, without contract and cheaper.

are you planning to unlock it yourself?

Because I think it's not as costly as the unlocked one :D

Yes and no. Locked phones (on contract) are generally cheaper IF you are the one getting the phone on contract and IF you stay with the carrier for the full two year term. Buying a locked phone from a third party typically ends up costing the same or more as the cost of the handset often isn't subsidized anymore.

Some of the reasons why purchasing a locked phone could make sense is that you either cannot make a contract on your own (1 year visa, no bank account, etc.) or you are able to purchase a used locked phone inexpensively (unlikely at this time with the iphone 6 as it is still too new). But you will typically be paying MORE by going this route.

"are you planning to unlock it yourself?"
Yes, with a R-Sim, in my country, that solution is very common :D

"Yes and no. Locked phones (on contract) are generally cheaper IF you are the one getting the phone on contract and IF you stay with the carrier for the full two year term. Buying a locked phone from a third party typically ends up costing the same or more as the cost of the handset often isn't subsidized anymore.

Some of the reasons why purchasing a locked phone could make sense is that you either cannot make a contract on your own (1 year visa, no bank account, etc.) or you are able to purchase a used locked phone inexpensively (unlikely at this time with the iphone 6 as it is still too new). But you will typically be paying MORE by going this route."

Idk how they bring SIM-locked iPhone to my country, and definitely from AU KDDI, Softbank, DOCOMO.
Maybe there are someone sell?

I see. Well that's a different situation then. Used iphone6's are selling on auction for about 10% less than retail, which implies that there will be little savings to a traveller compared to just purchasing an unlocked model and not having to deal with the sim spoofing headache. Note that locked japanese iphones are unlockable to a degree, and it depends on which carrier they are locked to. If buying in Japan then try to get a docomo model as they will factory unlock (for the original owner) for a 3000 yen fee.

OK, I'm understand.
Thank you all for helping me :D