I have to apologize in advance. I have lived only in Tokyo and hence do not possess information on the matter related to subject for other areas of the country. If you are interested, please stay with me and let’s talk about some ways of addressing cold and flu.
Local clinics do offer a seasonal flu shot for a reasonable price. The more typical way of preventing cold and influenza here is to wear a mask when in public and gargle throat once home. Masks are also worn as a form of courtesy: preventing people around you from getting sick if you already caught cold. You can sneeze and cough in mask, which stops germs from spreading.
Photo : Masaru Kamlkura on FlickrAnd of course, taking a hot bath before bed is a must, as it helps to prevent a body from getting cold. There is a variety of bath salts to warm up your body including citrus fruits and herbs. Hot springs onsen are particular popular during the cold season. If you are a fan, you might even want to try a bullet train with a foot bath. In 2014 the East Japan Rail Company launched the Yamagata Shinkansen between Yamagata and Fukuoka called "Toreiyu" (とれいゆ) with a hot bath on board. You can enjoy the marvelous sceneries passing by outside the window while soaking your feet in luxurious 15-minute bath.
What do you do once you start feeling the symptoms of cold? I think there is never a shortage of medicine to treat cold and flu in Tokyo’s drugstores (called yakkyoku 薬局). They are typically grouped according to which particular symptom you have: sore throat (nodo no itami 喉の痛み), cough (seki 咳), running nose (hana mizu 鼻水), high fever (netsu 熱 ), headache (zutsuu 頭痛), and so on. Cold medicine is called kazegusuri (風邪薬). There are however hardly any pills, and most medicine addresses a group of symptoms at once. For instance, this very common medicine called Paburon gold (パブロンゴールド) comes in a sachet with a powder inside, and all you have to do is simply dump the powder in your mouth before drinking water.
Photo : hiroaki maeda on FlickrSuch powders are also used as a means of prevention if you happen to be in contact with someone who already have cold. Of course, you can in any drugstore Ibuprofen and Acetaminophen, to help with headache pain, swelling/inflammation responses, and as a fever reducer.
The predominant majority of any medicine here comes in a form of a drink. A more natural way to treat cold symptoms is to take ginger drinks (it is called shogayu 生姜湯). Here is some handy recipe on how to make a ginger drink and store for later.
Photo : vanessa lollipop on Flickr
But if you are short of time, there is no need to actually buy raw ginger and peel and cut it yourself: any grocery store has all kinds of already pre-made ones: juices, instant powders and etc. The trick is to drink them hot.