1. Always wait for events to spend them. It's highly discouraged to buy anything from shop.
2. Make power your priority. Never farm for ninja fragments in events. Make rare exceptions only for those that you think are worth it.

spend all of them on mission gift box now!
i dont see anything better in the next weeks
get all med ref + u get extra rewards from the box

Thank you,

I just spent all into Mission Gift Box.

So after the event, save up all coupons and do it again?

The most value for money spending as an F2P is Lucky Board, which is held on the 1st week of every month. So save your coupons and spend it on that event.

PS. Next lucky board should be the weekly update of 1st to 7th June.

Don't waste all your coupons on the mission boxes now, that's a pretty dumb idea.
I'd say just have someone give you 10 easy missions to do each day and from that just invest all the points into Med refines and wait for a refinement event to come along so you can get that refinement level up.

I'd recommend you wait for certain events where they give you good deals on materials that'd highly benefit you in power, because as a F2P you'll need all the power boosts you can get to be able to at least even reach top20 on your server.

this looks interesting
can you give me an example of a good deal event?

I agreed that don't spend coupons on gift boxes.

for the past 7 days (included today) IF you received 10 mission cards from friend(s) everyday.

You should get 10 boxes a day. I did get 10 boxes everyday. That should make 150 points a day and I poured them points on med refine.
10 x 15 x 7 = 1050 points
1050/15 = 70 med refine.
(2 or 3 I don't remember from 9tails event)

Best event to use coupons, would be lucky board.

Best use of coupons is on lucky board, you get more med refines, moods, seals, etc. Don't waste coupons for ninjas also, always remember YOU ARE F2P YOU NEED POWER TO KEEP UP WITH P2W. Time and patience also is needed :D:victory:

and here i am, admiring op picture of ino ... never though she can pose lol

I mainly use my coupons for magas, refines, and other necessary things that contribute to my overall BP.

from what i saw so far since i started playing this game ( 4 months ago ) luky board is always on 2nd week of a month not first.

now to answer the OP , i would always save all coupons and spend them on luky board with few exceptions , that beeing if in a event there is a really good discount on a good ninja and you have enough coupons to buy him outright ( like gnw tenten, sailor sakura, sage naruto, and if u have the ninjas to make a full team with it ) otherwise just go for luky board only, and always prioritize power over ninjas with the few exceptions i mentioned above.

Its the 1st week in the sense where if that new month starts on Monday, Tuesday, Wed or Thurs, then lucky board will be that week. If the new month starts on the Friday, Sat or Sun, then the Lucky board will be the next week which is sort of the 2nd week.