iPhone usage for year abroad?

Starting from this October I will be studying abroad in Japan for a year (meaning I will have resident status).
My current phone has just broken and so I'm currently phone-less. I was considering buying an iPhone before I go but I'm now not sure considering the costs..

*I am pretty smart-phone reliant and would like to be able to use a smart phone in Japan as well. I would mainly use phone for social media + photos and would like to have access to data whenever I need it*

I was wondering if anybody had any experience or knowledge that could help me decide what to do.. Thank you in advance :)!

Do I:
1. Buy an unlocked iPhone here in the UK and use with a Japanese sim?
Finding sim-only plans or pre-paid seems difficult as most plans I have seen are for short-term travellers and ridiculously expensive for a year abroad. The Softbank website mentions a USIM but I haven't found more info on it.

2. Buy unlocked iPhone in the UK, buy pocket wifi and voice-only Japanese sim?This seems like potentially the cheapest option. Does anybody have any knowledge on what companies/ providers to use?

3. Buy iPhone in Japan with a contract that I then cancel after a year and then unlock phone for use in the UK (which seems impossible to do with Softbank iPhones)

4. Rent an iPhone for a year (letinternet.jp.com seem to offer this service but totalling up the costs for my year abroad would be around 100,000 Yen which is a bit steep considering I won't be able to keep the phone..)

5. Buy unlocked iPhone here, use for wi-fi in Japan + buy cheapest Japanese phone I can find for voice calls?

If anybody has any information that could help my confused self I would be forever grateful!

1. Buy an unlocked iPhone here in the UK and use with a Japanese sim?

That is a possibility. There are lots of services aimed at residents, but the info is primarily in Japanese which is probably why you aren't finding it. B-mobile is one of the more popular carriers.

However, if you have to get a new device anyway then it is probably easiest to just get a new phone and contract service with a provider in Japan and then cancel the contract when you leave. You'll just pay the balance on the handset and the termination fee, which overall could end up saving you a few ten thousand yen over buying an unlocked handset outright in the UK. Look into docomo. They will unlock their handsets while Softbank does not with certain models (iphones).

5. Buy unlocked iPhone here, use for wi-fi in Japan + buy cheapest Japanese phone I can find for voice calls?

This would be the cheapest. But in that case just get an ipod touch instead of the phone and save yourself a few ten thousand yen.

good.

If you want an iPhone, it seems you have no other option than to get a contract with one of the three major carriers. I have tried two docomo-based virtual carriers (b-mobile and OCN), and both were painfully slow even for basic usage. From what I gathered from various reviews, it is true for all others as well.

The only decent alternatives to major carriers at the moment seem to be au-based virtual carriers UQ mobile and mineo, which seem to offer service on par with the major carriers for less money, but with restrictions.

http://www.uqmobile.jp/en/
http://mineo.jp/

Basically, they are 4G-only and don't support iPhones, so you'll have to get a new Android phone. Officially, they only support au-branded phones, which you can buy on sites like Amazon at a reasonable price and which are sometimes not even sim-locked. For example, a new unlocked Galaxy S5 costs about 30,000 yen.

http://www.amazon.co.jp/dp/B00KXVOP3O/

You may also be able to use a SIM-free phone of a compatible model bought at home. UQ has a FAQ item about this, and they only say that they make no guarantee that it will work. Since they don't say that it will not work, my hunch is that it will work but they don't want to say it officially.

Then it's 1680 yen per month for voice + 3GB of data (at UQ), whereas at major carriers you'll pay at least about 5000 yen for that, and that's not including the price of the phone. Also you'll have no cancellation fees since the contract period for voice plans is 12 months.

Never mind, the phones are not unlocked, ネットワーク利用制限 refers to something else. Some of them seem easy to unlock yourself, however. For example for the S5: http://www.m-lab.info/android/97.html