Hi Davey,
I wouldn't exchange Yen to Euro. It will be very expensive to pay a commission fee at a private institution. I would just take out a decent amount of money at once with your Japanese bank card, and put it in your mother's/brother's/sister's/father's bank account, so that you then can take a bit here and there, or use it to order/pay things online.
Another option is to open a bank account in The Netherlands again, and transfer some money digitally through Paypal.
Normally I would try to avoid it, but since 1 Euro = 110 yen, you will still get a lot of euro for your yen.
If you are looking for an online bank, maybe knab.nl will suit you.