Menstruation is a deeply personal thing. Everyone's experiences are different, and while there's no shame in a perfectly natural bodily function, it's something most people don't like to be asked out.

So when it was revealed recently that girls attending a high school in Shiga prefecture were enduring probing questions from their teacher about their menstrual cycle, it became a controversial topic covered in Japanese newspapers and discussed online.

It seems the swimming teacher at this school asked female students to verbally declare how many days they menstruate, aiming to prevent girls from using it as an ‘excuse’ to miss swimming practice.

Shockingly this has been going on for four or five years, and the complaint was just recently lodged with the prefectural board of education by parents of the students.

It is claimed the teacher took no consideration of surroundings when asking the girls, making them give details of their period in full earshot of others.

This is not just a gross invasion of young people’s privacy by an authority figure, it’s also completely unfair to apply a uniform policy to something as wildly varied and unreliable as menstruation.

While some girls are in debilitating pain for over a week, some barely even notice their period. Not to mention irregular periods, meaning some can’t predict when their next menstruation will come, which this swimming teacher would probably interpret as a lie to get out of swimming practice.

According to the Asahi Shimbun, the male swimming teacher said things like, ‘if you’re on your 8th day then you can swim. One of your seniors in on her 4th day and she’s in the pool.’

Although this shows the teacher clearly has no clue about the varied experiences of people who menstruate, he still saw fit to dictate who was feeling well enough to swim and who wasn’t.

Worryingly, after the story broke, women claimed in online comments that they had been through the same experience, some even saying that they had to swim regardless of whether they were menstruating or not.

After receiving a backlash, the school has put a stop to the practice, and the principal has given a statement to convey that they are 'reflecting on the mental stress it may have caused students'.