The financial future of some Japanese universities has been placed in jeopardy following the exodus of many thousands of foreign students in the wake of the massive earthquake, tsunami and potential nuclear catastrophe that hit the country in March. More than 15,000 people were killed in the devastation that resulted from the natural disasters suffered by the north-east of the nation.
Those foreign students who subsequently fled the country included tens of thousands of Chinese, who make up the vast majority of the overseas contingent at Japan's universities.
The exodus left Chinese students contemplating ruined studies, but it also highlighted the fact that overseas recruitment is essential to many universities in Japan, an ageing society where the flow of home students has reduced.
Keenly aware that foreign students will be missed on many levels, the Education Ministry's tactics include buying free return tickets for foreign students who are hesitant about returning to Japan. In another scheme, aimed at bringing back tourists, the ministry is paying students to take short holidays around Japan and then report their experiences on Twitter.
Some argue that the government, which is committed to boosting overseas student numbers by 2020, must step up its internationalisation efforts and force universities to look beyond their reliance on Chinese students.
For university lecturers in Japan, March was the spring recess and academic life was due to rekindle only on 1 April.
"It was vacation time, so teachers were relatively free to travel," said Paul Snowden, a former dean at Waseda University in Tokyo. "Many took that chance, against a background of uncertainty and concern bordering on fear, which was fuelled by alarmist rumours as well as ignorance of what was going on.
"The quake itself, even in Tokyo, hundreds of miles from the epicentre, was strong enough to scare anyone. And the following few days of paralysed transport, no phones and panic buying of rice, water, toilet paper, batteries and petrol were quite enough to persuade those who could to get out."
And flee they did. According to the Justice Ministry, more than 470,000 foreigners left the country, at least temporarily, between 12 March and 1 April.
The Education Ministry is only now preparing figures on the number of students and foreign teachers caught up in the exodus. But Immigration Bureau of Japan statistics give a snapshot.
More than 70,000 of the 86,000 Chinese students left the country in March. The sudden stampede closed down local Chinese restaurants, now bereft of their student labour.
Of those 70,000 Chinese students who left, 22,000 remain absent. Parental pressure, particularly from one-child families in China, had a great bearing on those decisions to quit Japan, Mr Snowden said.
Among those to leave was a reluctant Zha Zha from Shanghai, a final-year student at the private University of the Sacred Heart in Tokyo. She was attending a rehearsal for her planned graduation when the quake struck on 11 March.
"We were in an old part of the faculty, and the building just kept on shaking and shaking. It was the first time I experienced an earthquake, and it scared me to death," she said.
The slow return
Despite the trauma, and despite subsequently learning of the tsunami and the nuclear accidents at Fukushima, Ms Zha was determined to stay.
"My mother was in Tokyo for the graduation ceremony, and she begged me to return immediately with her for fear of radiation from the plant. Despite official assurances, she doesn't trust the Japanese government. So even though ticket prices were horrendously expensive at the time, two days later we left."
Later Ms Zha was able to persuade her fear-stricken family that Tokyo was away from the worst of the danger and that she had to return to find the work she wanted in Japan. Hesitantly they let her go, and a month later she resumed her job-hunting in Tokyo. Her graduation ceremony, however, has been cancelled for good.
At Waseda University there was a similar pattern. The so-called "fly-jin" ("gai-jin" means "foreigner" in Japanese) among non-Japanese students and foreign staff departed and then returned within the month.
The university has Tokyo's highest proportion of foreign students, according to Mr Snowden, but only 30 students out of 900 undergraduates have taken leave of absence for a semester or two.
"A far higher proportion of 200 or so on a one-year programme have left, but that seems to be on account of instructions from their home institutions, mostly in the US, to abandon their courses, which many students themselves were reluctant to do," he said. "Oxford sent its students to Osaka for the duration of the vacation; they're back with us now."
Japan's Yomiuri Shimbun newspaper has also attempted to piece together just how many students the nation has haemorrhaged since the disasters. Its survey suggests at least 4,330 foreign students, enrolled at 71 universities in Japan, have left the country for good.
Such a loss has come at a bad time for Japan's private universities, many of which are in the middle of a sharp decline in their fortunes caused by the country's plummeting birth rate.
"Many of the less highly ranked institutions probably will suffer from any decline in numbers of less talented (and thus educationally less motivated) foreigners who enrol, pay their fees, get a visa and then disappear into the employment black market," Mr Snowden said.
Turning the taps on
To shore up those ailing universities, pre-quake Japan had formulated the "300,000 International Students Plan" with the aim of boosting its foreign student intake by 2020.
Japanese universities have suffered in international rankings because of their sparse numbers of international students and staff. Only two of the country's institutions appear in the top 100 of the Times Higher Education World University Rankings.
"We value our foreign students...We are keen to invite more such students to Japan," says Junsaku Mizuhata of the ministry's Higher Education Bureau.
According to Mr Mizuhata, 86.6 per cent of non-Japanese students have returned to Japanese colleges to study, although in the Tohoku region, worst hit by the quake and tsunami, the figure is only 35.1 per cent.
Such figures could bring some comfort to the private universities who "have no other real source of students or income as the country ages", said Terrie Lloyd, an entrepreneur and commentator in Tokyo.
"The key here is diversity. If the government wants foreign students, which I agree creates a tremendous amount of future goodwill as well as future foreign residents and workers, then it needs to expand its assistance to universities recruiting elsewhere in Asia (beyond China)," he said.
"Economic circumstances will ensure a strong flow from most countries, but there needs to be a cohesive and deliberate policy to turn the taps on. As yet, while small steps are being taken, we don't see that happening."
Meanwhile, Japan faces further uncertainty, as many scientists now agree that the Tohoku quake caused a serious rupture of the tectonic plates off Japan's eastern coast, potentially creating the conditions for another monster quake in the next month or so. And the contamination issues at the Fukushima nuclear reactor may take years to solve.
Shuttered nuclear power stations also mean a potential energy crisis, and with many colleges now extending the semester to include August to make up for a lost April, power cuts in a hot and humid Tokyo summer could make life at universities hellish.
Michio Nitta, professor in the Faculty of Political Science and Economics at Tokyo's Kokushikan University, said: "The next challenge is how to cope in summer with a limited supply of electricity. College presidents are praying that it will not be a hot summer, at least in July."