I need to vent a little about this because I've got a few rather selfish-sounding messages about these (along with some polite ones).
Please don't message me about getting one of these unless I announce I am going. It is a ticketed event (1500 yen, must be purchased days in advance) plus it costs 1000 yen in train fare. These tickets are sold for specific days and time slots. It will take at least 4-5 hours of time for me to go there and back, buy the poster tubes and boxes, make the slips, and then take them down to the post office. Because this is a limited-time event, THERE IS A LIMIT on what I am allowed to purchase. I'm not going to be the bumbling gaijin going in there buying 20 posters even if I was allowed. This means I'd have to go with a friend whose schedule matches mine, and matches the time slot available to go.
I'm a pretty laid-back guy, but I don't appreciate requests for 5+ plus posters, and acting like me going to get them for you shouldn't be paid just because the event looks interesting to you. I'm a married man and have my own view on what should be done on my days off.
Rant over. I feel better.
Edit: For clarity, a couple people requested over 5 for just themselves.