Cash Shop Specials: 5/8 - 5/14

Could you please clear something up for me? the coupon you buy gives you 5 tickets, which are tradeable and have no expiry date. I'm wondering then, if the tickets will work once the items are removed from the cash shop? I'd assume you'd always be able to use them, since there is no expiry date. But it can't hurt to know just in case. thanks!

I have tickets from previous events; mirrors or some other gachapon-esque event.
I know the tickets worked but I don't remember if they dropped anything.