Canker Sore Treatment Tablets in Japan

    I've been prone to cankre sores since high school, when stress and dietary failings led to my mouth frequently being home to at least one small open ulcer, and I tried as many treatments as we could find but nothing worked long term. 

    I then grew up, adapted my diet, found other ways of dealing with my stress, yet still the other day I woke up to find the little painful knot on my lip had grown into something unmanageable. Something had to be done. 

    The kanji you'll need for medicine related to canker sores is 口内炎 (kounaien) which is delightfully easy to remember if you know some basic kanji. mouth. inside. FIRE FIRE. That describes them pretty well, I'd say.
    Medicine for these tends to come in three types: tablets that you place over the offending spot, creams, and sprays. Both the creams and tablets aim to do the same thing: cover the thing so it can heal without being constantly re-injured by things like talking and eating. The sprays numb it and should help disinfect as well, but I haven't had much luck with them. I've also tried creams back home and almost always had the same problem with accidentally diluting the solution via saliva or constantly poking it with my tongue and rendering it ineffective.
    So I tried the tablets.

    This is essentially a canker sore band-aid, and the best thing about it is that one little tablet will expand to take over an oblong ulcer more than twice its size, so there is no need to use more than one per sore.
    In addition to the great box illustration, the instructions on this brand came with helpful pictures for the kanji illiterate, like me.
    The tablets have an orange side and a white side. As it shows in the picture, the white side should make contact with the sore. The orange side should touch your finger. This works better if the sore is somewhere it won't be bothered, like between the lip and gums. Mine unfortunately was on an easily exposed part of my upper lip, so keeping the tablet-band-aid on the sore was a little tricky, but it stayed on well when I put it on before bed.
    I think the tablets did do a good job overall. My mega-sore healed within a couple of days of putting one of these tablets on it, and that was after suffering with the sore for more than a week.
    
This is what it looks like when you put it on and after it has done its job. If you need to re-apply, you can. There's a bunch in every package.

So if you're stick with a pain in the mouth that just won't go away, treat your inner-mouth-fire-fire with some over-the-counter tablets. They worked for me, anyway.