Its not exactly f2p.Hokage minato is a money ninja but he's been in the lucky * and lucky stars wheel once(i got mines from the lucky stars wheel with a few a couple hundred coupons),but he's a money ninja which you have to get from like,ingot recharge events which i haven't seen him in a really long time.And for Gaara,you can get frags for him in the black market by getting 3-5 frags but it'll take a while to get him to 3 stars.He's actually in the daily recharge thing or whatever its called which if you recharge 50 ingots a day,you get gaara frags and some other stuff.