Japan's Inane Marijuana Policy

I come from San Francisco and go to school in Portland. My whole life, marijuana has been illegal enough to slightly inconvenience would-be smokers, but barely more. The consensus tends to be that it's much less harmful than alcohol, an excellent appetite-inducement tool for those going through chemotherapy, and a good alternative to opiate painkillers.
This is not the case in Japan, where four students at my school were just arrested, and will likely be imprisoned and later deported, for marijuana possession. I received an "urgent" email from Waseda in my inbox today, and on clicking it, I was presented with the following on the student web portal:

Warning Against Illegal Drug Usage

As has been widely reported by the mass media, many people have recently been arrested
for involvement with illegal drugs. For the younger generation, especially university
students, there is a great temptation to engage in drug-related activity. This has become
an extremely serious social issue, partly because the smoking of cannabis (or marijuana)
is so easily done, no special devices or equipment being necessary for its recreational
use – it is simply smoked like a cigarette…..

…Tempting words are often used to lure people into drugs: "Recover from your
fatigue," "Refresh your mind," "Take the easy route to dieting." Such encouragement is
vicious and despicable, first of all because the information is based on falsehood.
Secondly, and far more importantly, those who are foolish enough to fall for such lures
all too often end up physically and mentally ruined, perhaps leading lives of crime.
There is no "innocent" or "harmless" way to take illegal drugs. In Japan, possession
alone is sufficient to lead to the most dire of social punishments. Engaging in drug-
related activity is utter stupidity.

DO NOT BECOME INVOLVED IN ILLEGAL DRUGS!

Does this memo represent a wholly ignorant, paranoid viewpoint on marijuana? Of course. On the other hand, I have little sympathy for the smokers- they knew what they were getting into, and risking imprisonment, a permanent ban from the country, and a crippling impediment to future job searches is pretty stupid, too.

For more info:

Waseda Weekly article on the incident (were this America, the student paper would be a pro/con piece, if not an outright rebuttal to the administration).

Good article at Japan Probe about "Japan's Growing Marijuana Problem."

Asahi Shinbun article on the arrests.