Where to find a poster tube in Tokyo?

I need some poster tubes to send a few posters by mail. I asked at the post office, no luck. I went to 100 yen shops and stationery supplies shops, still couldn't find anything.

All I could find was on Amazon, but there are only professional poster holders for art students, which are too big and too expensive. I just need something extremely simple made from very solid cardboard.

Anyone has any ideas? I would appreciate any kind of help!

Large stationery shop should have them, and I know post offices at least used to have them too :(

If some more 100-yen shops don't get you good findings, try Tokyu Hands if there is one near you. Ask for "kami-zutsu" (paper tubes, literally).

Try different 100-yen shops. I had to shop around and finally found some in different sizes at Daiso.

@AK: Thanks for the suggestions!

@yllwsmrf: Really? I went to a few Daiso shops, including a few HUGE ones, couldn't find anything...do you happen to remember which Daiso was that?

Sorry it was some years ago and I don't recall. 100 yen store stock is very hit or miss and I only remember seeing them occasionally. Its probably better to just buy the more expensive plastic ones than waste a lot of time searching stores for them.