Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
What type of school is it?
You have certainly not overstepped any line whatsoever - my only concern is how you deal with this with regard to the school.
As someone with Parental Responsibility you have every right to contact the school and are entitled under Uk law to speak to them directly
The problem is what you do about this
If it was a Uk school then there would be no problem whatsoever - they could simply be reminded of the law on this matter and they would continue to give you the information you request.
Unfortunately since it is in Japan then the position is less clear.
A simple formal letter to the school confirming that in the Uk you are indeed entitled to have whatever contact with the school you wish and they would have to deal with you, and that you hope that they will honour the british law on the matter and copy it to your ex.
Please ask if you need further details
If the school was in the Uk there would be no problem.
Equally if they are prepared to follow Uk rules then all is well.
Unfortunately I do not know what Japanese family law says on the subject