You should post this kind of thread in General Discussions since most of the Users here are in that section as you are asking for advices and not reporting bugs or giving suggestion for the game ..

But okay, for your topic, better go for Lucky Board than spending in Wheel of Fortune .. If you only targets the ninja in the Wheel then it is not recommended to spend your coupons there because you may end up with nothing since that Wheel event involves RNG or in plain word, Luck .. While on the Lucky Board, everytime you throw a Dice, you will get a certain item for power and a point that you c@n use to redeem something from its redeem shop .. A power-up item or ninja fragments ..

Thanks for your answer, it is very helpful. This is the first time I use forum and my English is bad so I posted on a wrong place. Sorry!

I see, no worries about that .. It's understandable that you're just new here in forums .. If you need help next time about something you can try and make thread in General Discussion so you can get more help, but if you're gonna report something like Bug or give suggestion for the game, then Bugs & Support section is the right place for you to make thread.

Anyways, welcome to the Naruto Online Forums :D .. hehehehe