As this year’s elementary school graduates enter junior high school in April, one of their biggest concerns will be which extracurricular club to join.

Known as bukatsu, the clubs are so central to the Japanese junior high and high school experience that they not only determine students’ friendships but also affect their later development.

But this long-held tradition is now coming under fire, and from an unexpected quarter: The teachers forced to supervise them say the expectations placed on them are inhumane and driving them to exhaustion.

We look at the emerging controversy over extracurricular clubs:

What is bukatsu?

First-year pupils are typically instructed immediately after enrollment to join a bukatsu outside their classroom hours, with their choices ranging from athletic activities, such as soccer, baseball, basketball and swimming, to nonathletic pursuits, including art, calligraphy, tea ceremony and brass band.

Students practice their chosen activities almost daily, mostly after school, over the weekend and sometimes even before school. In what resembles a military culture, strong vertical relationships permeate their activities, with younger students often expected to show unquestioning subordination to their senpai masters a year or two older.

Since each activity usually takes place within the premises of schools, teachers are tasked with supervising whatever club they are assigned to and coaching the members — although some teachers are no expert in what they are supposed to teach.

Bukatsu is technically regarded as a “volunteer” activity under the education ministry’s current guidelines. But many junior high schools and, to a lesser extent, high schools pressure students to join one.

What is the history of bukatsu?

Originally incorporated into the school curriculum around 1970, the precursor of bukatsu — kurabu katsudo (club activity) — remained an official subject until 1998.

But even before that, many schools had reduced bukatsu to the after-school activity that it is today in order to cut the amount of class time under the yutori (relaxed) education policy of the early 1980s through the mid-2000s that was designed to ease student stress, according to Hiroshi Nishijima, an associate professor of education studies at Tokyo Metropolitan University.

Its 1998 withdrawal from the school curriculum, however, didn’t put an end to the culture of bukatsu, because many teachers back then regarded it as an effective way to teach unruly students discipline, Nishijima said.

What are the pros and cons of bukatsu?

Bukatsu is often credited with improving students’ sociability, perseverance and the spirit of teamwork. It also gives them easy, low-cost access to whatever athletic or artistic activities they find interesting, at times even influencing their choice of a future career path.

At the same time, the clubs take a heavy toll on teachers.

Complaints are rife that teachers who supervise the clubs are overworked to such an extent that they barely have time for their private life, causing some to have mental breakdowns or marital problems.

In 2011, then-26-year-old Hirohito Maeda, an Osaka teacher, reportedly died of heart failure after toiling over his duties both as a class teacher and bukatsu coach for months on end.

Indeed, the OECD Teaching and Learning International Survey in 2013 found that junior high school teachers in Japan spend 7.7 hours a week supervising extracurricular activities, more than triple the OECD average of 2.1 hours.

An education ministry 2006 survey showed 76.2 percent of junior high school teachers nationwide were charged with overseeing bukatsu activities.

How tough do teachers have it?

Ryusuke, an English teacher in his 30s in central Japan, had until a few years ago been a devoted coach of a tennis team he was assigned to. His dedication, however, didn’t last after he realized his private life was falling apart.

Aside from spending a minimum of two hours supervising the team after school, Ryusuke found himself inundated with coaching duties every weekend — sometimes up to 12 hours a day — particularly when he accompanied his team on out-of-town tournaments.

On his busiest days, Ryusuke, who asked that his surname be withheld, said he did 100 hours of overtime a month or worked for 90 days straight. He barely had time to interact with his own children at home and prepare for his English class. And most of his extra work went unpaid.

In general, teachers don’t get paid for the overtime they do supervising clubs on weekdays.

Their weekend coaching duties are supposed to be paid. But the daily allowance typically amounts to a few thousand yen (a maximum of ¥4,000 in Ryusuke’s prefecture), far from enough to offset the expenses they incur, including purchasing training equipment and paying for transportation.

“It’s almost like you’re paying to overwork,” Ryusuke said. “The way I see it, bukatsu is a serious labor issue that borders on illegal.”

What steps are being taken to counter the situation?

Ryusuke and five other like-minded teachers recently launched an online petition demanding a revision to the education ministry’s current guidelines so teachers can decline to supervise club activities.

Today’s guidelines stipulate bukatsu is an option for students but says nothing about the obligation for teachers.

This ambiguity has customarily given school principals leeway to assign rank-and-file teachers to a club activity at the beginning of each school year. Ryusuke tried to defy the tradition last year by requesting he be spared bukatsu duties, to no avail.

On Thursday, the campaigners submitted 23,522 signatures to education minister Hiroshi Hase.

What needs to change?

The education ministry is aware of the problem surrounding overworked teachers.

In proposals last summer, an advisory panel to the education minister called for outsourcing bukatsu activities.

Nishijima of Tokyo Metropolitan University agrees.

Even today, mothers and fathers volunteer to coach students, but the biggest challenge ahead is “how to systematically support such individuals and evaluate their coaching skills,” he said.