The citation is already in my post : the pdf linked is the official list of controlled substances published by the Narcotics Control Departement of the Japanese Ministry of Health, Labour and Welfare where you can see methylphenidate is a controlled substance of the class "Psychotropics". The web site linked is the one of the NCS with the details of the procedures for the importation in Japan of controlled substances, including psychotropics. I guess I can provide a direct link to the relevant section :
here.
I don't think it contradicts what you posted. Ritalin is not banned in Japan, it's just prescribed differently than in the US. And you do not need to request a Yakkan Shoumei form (roughly, an importation permit) for it unless you bring more than 2.16 grams (source is
a table mentioned in the above-linked site), which sounds like a lot to me since the pills contain 10 mg and average intake is 2 or 3 a day (so 775 mg in a month). Your quote seem to imply that Yakkan Shoumei requests for Ritalin are usually refused, but that's probably because it's difficult to argue personal use for a month when you want to bring almost 3 times the average prescribed amount.