Japanese Bank with no International/Conversion fees?

Do 7-11's abroad also contribute to free withdrawals as most Japanese banks offer?

No. ATMs in 7-11 in Japan are owned by 7-Bank, a Japanese bank. ATMs in 7-11s in Thailand are owned by a Thai bank, which as far as I can remember varies according to location.

When you say "0 withdrawal fees" what do you mean?

Do you mean that the bank will refund the ATM fees charged by a local bank overseas? Then no I have never heard of a Japanese bank that will do that. They will only refund ATM fees that are incurred when using an ATM at one of their 'partner' banks in Japan. I've never heard of a Japanese bank that refunds overseas ATM fees.

Do you mean that the bank won't charge a transaction fee for making a withdrawal? Then yes SHINSEI for example does not charge a transaction fee for withdrawing money while outside of Japan.

HOWEVER, Shinsei does add 4% to the exchange rate. So for example, if the exchange rate was $1 to ¥100, the rate would increase to $1 to ¥104.

But, it might be better to pay the fee. For example, AEON bank charges a ¥216 transaction fee and then only adds 1.6% to the exchange rate. So if you are taking out ¥10,000 equivalent at the example rate above, you would pay ¥216 plus and an extra ¥160 in exchange rate, or ¥376 total at AEON and ¥400 at Shinsei. Rakuten Bank charges no fee by adds 3.024% so in the same situation the fee would be ¥302, by far the best deal.

To avoid the fee imposed by the local Thai bank, find a local bank/ATM that doesn't charge a fee for using an ATM card from a Japanese bank. Your best bet would be to find a foreign bank, preferably a Japanese bank. The place to ask about that is /r/Thailand or /r/ThailandTourism. My guess is that this question has been asked a bunch of times before, so you all you need to do is search.

/r/japan Thread