Third graders at the Chaoyang district school in Beijing received their first lesson in sex education in the form of a toilet tour on Monday.
Giving children an opportunity to peek into the other gender's bathroom is a way to help boys and girls understand gender roles under the new initiative, educators said.
"Children tend to be curious about the bathrooms of the opposite sex," sex lecturer Hou Wenjun at Anhuili Central Primary School told Beijing News.
Hou believes that education starts with curiosity. "A tour to the bathroom lets children see what behavioural differences there are between the two sexes."
Now an official part of the school's curriculum for grades one to 6 (ages 6 to 11), sex education begins with the fundamental subject of fertilisation, a report in the state run Global Times said.
Students first viewed a PowerPoint presentation illustrating how sperm fertilise eggs.
When asked how gender is determined, the students came with guesses such as "it depends on what Mom wants" and "bigger eggs grow into boys while smaller ones make girls."
Visiting the bathroom can be a good technique in teaching gender codes to students, Zhang Meimei, sex education expert at Capital Normal University said.
"The bathroom of the opposite sex can be a mysterious place. I have known a lot of third- and fourth-grade boys who would sneak into the lady's room just to see what it is like," Zhang said.
"Sex educators can take this curiosity and turn it into knowledge of social norms regarding sex.
Kids are going to learn why society expects men and women to behave differently and not just in the bathroom," she said.
Zhang is leading a pilot research program on sex education practices in Beijing, and Anhuili Central Primary School is now cooperating in research.