Engineering the Invisible: How Tokyo’s Hidden Infrastructure Is Opening Doors for Girls in STEM

Girls visit the Magome Rolling Stock Depot during a TMG-organized office tour.

Rails, wastewater—and the women engineers who keep Tokyo running. This June, 18 junior and senior high school girls stepped into the capital’s often unseen world of science and engineering, discovering how STEM silently supports everyday life—and how it may shape their own futures.

Bridging the Gap: Why STEM Matters

STEM—science, technology, engineering and mathematics—is essential to modern society. Yet in Japan, a gap persists: while girls consistently achieve strong results in these subjects, relatively few go on to pursue STEM-related studies or careers. 

To help address this imbalance, the Tokyo Metropolitan Government (TMG) has, over the past four years, organized office tours for junior and senior high school girls, connecting them with real-world applications and female role models across industries.

This June marked a new step. For the first time, students visited technical sites that directly support the daily lives of Tokyo’s 14 million residents, while also engaging with women engineers at the forefront of these fields.

Speaking at the event, Vice Governor Matsumoto Akiko highlighted a pressing challenge: companies are eager to recruit women engineers, yet too few candidates are available. “We believe this is a tremendous loss. Why does this happen? Is it due to a lack of role models, or persistent stereotypes about career choices? If so, Tokyo is committed to changing this situation.” 

Inside the Systems That Keep Tokyo Moving

A tour participant tries lifting a section of a real train rail.

As part of this inaugural tour, participants visited two key facilities. At the Magome Rolling Stock Inspection and Maintenance Depot of the Toei Subway, students observed inspection and maintenance operations up close.

When they were handed a 10-centimeter section of a train rail weighing about five kilograms, curiosity was instantly sparked among them. 
“What is it made of?”
“Does it rust?”
“How often do rails need to be replaced?”
Each question was met with clear explanations.

Some students were even given the rare opportunity to experience elements of train operation procedures and pantograph handling. 

From Wastewater to Life-Supporting Systems

Tour participants look into a pool where guppies swim in treated wastewater.

At the Ariake Water Reclamation Center, the focus shifted beneath the surface—literally. Students learned how wastewater is treated and returned to the urban ecosystem.

Watching the process step by step, the students expressed surprise at every stage. By the end, the water had been purified to a level capable of sustaining small fish.

“Can you guess what kind of fish these are?” a guide asked, pointing to clear pools of treated water. 

After a lively exchange of guesses, one student proudly exclaimed, “Guppies!”—and she was right.

Voices from Women Engineers

Female engineers at TMG share their stories with middle and high school students.

Another highlight of the program is a panel discussion with female engineers who shared their career journeys.

An engineer involved in flood resilience planning for Tokyo’s subway system emphasized the importance of teamwork, noting that the experiences gained through collaboration during school are invaluable—and the ability to communicate ideas clearly remains essential in any field.

Another engineer, who works on the design and planning of subway stations and bus shelters, highlighted the satisfaction of infrastructure work: although projects take time to come to fruition, seeing completed facilities enhance public safety and convenience brings a strong sense of fulfillment.

Both engineers, who are raising children, also spoke positively about work arrangements that support work-life balance. 

TMG allows employees to take up to two hours of partial leave per day until a child reaches the third grade of elementary school. One engineer described the system as extremely helpful. She added that she makes full use of it as a mother of two preschool children.

They also emphasized that being a woman does not present a disadvantage in technical work environments. At one site, 14 of 52 engineers are women, and in the architectural field, women sometimes outnumber men in younger generations. At another, where she initially joined as the only woman, the number of female staff has increased to four out of 36, with one currently on parental leave.

An engineer from the sewerage bureau described infrastructure as “something so fundamental that it is often taken for granted and goes unnoticed,” and said she takes pride in sustaining this everyday normalcy.

Inspiring the Next Generation

A water quality specialist demonstrates how treated wastewater is tested.

The engineers' dedication left a lasting impression on the students. 
One participant, reflecting on wastewater treatment, expressed surprise at the role of microorganisms: 
“I didn’t realize they could absorb pollutants. It made me think this technology could help improve water quality in other countries.”

Another spoke about how the experience reshaped her view on technical careers:
“I used to think these jobs involved mainly physical work, but I realized that what we learn in school—like science and math—is directly connected to real-world problem-solving. Seeing the labs and engineers’ mindset, I honestly thought it was really cool.”

More tours are scheduled for July and August. 
There are many majors out there in college. Don’t rush—take your time, look around, and discover what excites you.