Wait for mission mobilization general next week or the one after.

Sage naruto will definitely be there (he seems to be a refular on that event). It is a good one for f2p since the packs have some good stuff. Don't expect a jackpot ninja though. 1500 boxes openned not a single ninja... Oasis odds.

By next week you mean this one? And how much does Sage Naruto cost in the mission mobilization event?

You can get up to 1050 points for free in this event, sage cost is around 40-50 points per frag (cant remember, you can check previous event threads with mission mobilization event and dig for picture with ninjas to have exact value). Then, you can buy box with fixed drop of 10points and 1 random item for 20 coupons. While by looking at the points itself its kinda expensive (80-100cp per frag) you will get some of the value back in cave keys, medium refine and medium threads or even a rare ninja (but dont hope for those).

dont buy sage naruto youll get him eventually for now increase your power that should work better especially with you being f2p,with your coupons thats youve saved till now you can easily get a lot of power with refines+keys

save more coupons and get minato flak jacket instead, works good with wind main chase repulse cause knockdown 2x and try using it with roshi/utakata if you can save for them

Don't listen to what ppl say to get Minato flak jacket even if you don't have enough power to cater him...He required lots of power base...if you don't have that much power and initiative...Don't ever buy him... it just useless...Just focus on your power and initiative...until you get 50-60k power...