A high school in Japan held a ‘Sex Change Day’ this week – where boys dressed in skirts, and girls wore suits and ties.

On Tuesday, Fuji Hokuryo High School, in the Yamanashi prefecture encouraged students to swap uniforms with the opposite sex for a day.

Despite the name, the event has nothing to do with reassignment surgery – and was simply intended to promote a message of tolerance and acceptance, and to challenge traditional notions of gender.

Japan’s school system usually strongly relies on gender roles, with gender-specific uniforms for boys and girls still expected.

However, the take-up of the event was surprisingly high, with just 8% of students indicating that they did not support the event, and over 300 taking part.

As part of the day, students were taught about perception of gender, and how changing gender can influence those around them.

According to the school’s principal, the day might become an annual event – with the main complaint on the day was boys complaining that their legs were cold wearing a skirt.

Vice Principal Hirofumi Miyashita told Japan Real Time: “This is a project for students to observe things differently”, without being bound by gender.

He added that the event allows pupils to try something new.