I signed up to longecity today after reading your post, for no other reason but to warn you to be extremely careful with what you import into Japan. I resided in Japan as a foreigner for 21 years and observed on more than a few occassions, foreigners having to go through extreme hardship to say the least, for importing medicines from abroad, either in person on arrival or by mail.
Since this is my first post, I am unable to add links to more information until I have more posts. In fact one case I know of prompted a US State Deptartment website warning Americans considreing travel to Japan not to carry with them any Adderall, Dexedrine or Vyanase into Japan. I'll add that I do not know the specifics with importing Ritalin or Concerta. To the Japanese government, importing the prescribed amphetamine salts is the same as importing heroin, amphetamines are illegal in Japan and it makes no difference to the authorities if it is prescribed to you outside Japan. Similarly, for example, don't expect anyone in Dubai or the state of Missouri to allow foreigners coming in from Colorado to pull out their medical marijuana card as defense for the weed in their suitcase.
It is absolutely illegal to import Deprenil (Selegiline) into Japan, due not so much to selegiline's drug effects but rather because a metabolite from some forms of deprenil or selegiline can be found in the urine of users which shows up in urine tests as if the person has been taking amphetamine/methamphetamine. Since I can't add the link, please search for it. (My plug, GINYF (Google is Not Your Friend), instead use the anonymous Duck Duck Go search engine 
To the powers that be in Japan, methamphetamine historically has wreaked havoc in Japan for ages , so therefore stopping it's usage is very high on police enforcement efforts and they feel arresting users works.
In Japan having a an amphetamine presence in your urine is considered "drug possession" you need not have any drug on you, nor in your home, internal presence in your pee alone of a metabolite is considered "possession." In every case I came across, violators receieved about 3 years in prison in horribly decrepid, ultra crowded, WWII strict boot camps that would blow anyone's mind.
Police regularly grab people walking down the street, particularly if their top teeth are gone, assuming they are meth (kaksezai) abusers, they haul them in for urine tests without recourse, and if postiive, they get the three year penalty. The prisons are full of such men, most are repeat "offenders."
Japanese customs are quick to monitor foreigners mail, far more quickly than they might of Japanese citizens. Remember, the drumbeat is that most evil comes from outside Japan. Should they find anything in your mail they presume is an illegal drug, they quickly raid your home with a team of experts who tend to be meticulous during the search.
Any person found to import what they believe to be illegal substances will be immediately arrrested after the home search, abducted to a station and subjected to a urine test once incarcinated. Often the abductee is not allowed to call anyone for as long as 22 days. Interrogation is in every case 22 days for first round, where without a lawyer they are subjected to ruthless interrogation. Remarkably, 99.8% of those arrested admit to whatever it is the police claim they did. This interrogation period without a lawyer is a long running bone of contention with the US State Department as well as with Amnesty International, as are the draconian prison conditions.
My advice to you is, do not attempt to import any substance by mail which is illegal including selegiline. Secondly, should you do so, be certain you have no other illegal materials in your home such as marijuana when awaiting your mail order.
I am and American who lived in Japan for two decades until recently and watched a few cases where people known to me were taken down from mail importations and later endured long prison sentences. Japan's judicial system is corrupt as can be, prosecutors and judges sit in the same office, wink wink, nod nod, and trials are phoney kangaroo charades mostly for the west's placation, yet from my view, sentecing is always decided before the trial begins. Police claim their 99.8% conviction rate is because they are so good at what they do, I'd laugh but I am have long been a member of Amnesty Internation and see it otherwise.
Japanese powers that be love to take a foreigner down, as it suits their premise that most evils in Japan come from abroad, not from within, so presecutors and judges get a feather in their cap when they take another foreigner down. They also like to avoid making arrests or any sort of trouble with the entrenched yakuza who they most often allow to run their criminal operations as they please.
I will try to add some ideas for milder, legal herbal alternatives for the OP in a later post if I can think of any.
