I used to be one of those who do convoys and get constantly plundered. I've had my rants and complaints in the past regarding how unfair the system is, it really is atm. Now I started on another server, and it came to a point that I can take on quite most of the players in the server, so I started plundering to see how it works. As of now, each successful plunder gives you 50 coupons, do it 3x a day and you'll get up to 150 coupons max everyday just from plunder alone. Now 150 coupons is what entices people to do plunder; it's just too good to miss out on. Sure there are pure spiteful people out there who do plunder just for the sake of tormenting others, but there are are other people (like me) who do it just because we had to, in order to advance ourselves as best we could. Plunder isn't all that easy either, several others like me still fails 1-2 plunders, and we get 0 coupon for each failed attempt.

Don't worry though, rumor has it that Naruto Online Version 4.0 will arrive soon. In that update, the convoy/plunder system gets changed. Successful convoy will yield only 30 coupons, but when someone plunders you, you'd only lose 5 coupons (thus, you will get a minimum of 25 coupons.) Also, the update will make it so that you can do both convoy and plunder in the same day.

There is one free one for top 50 ranked players

Any more you need to use a ticket or ingot. (i.e. first one for non-top-50 and 2nd/3rd for everyone)

It's a consumable item that allow you to do an extra SS, there is one type for plunder and another for convoy.

They are permanent and you c*e two in the same day (for 3 SS plunders)

You earn them in events and it can drop as a result of S convoy/plunder