I'm not sure if you figured this out but the card flip system in Team Instance does not give choice of rewards when you select a reward. If you receive a stronger ninja tool you would automatically get the message of getting a strong ninja tool right after the match ends and before you have the chance to select a tool. I'm sure the same mechanism is applied in Treasure Tool essense.

Well I had to point it out since it seems like you didn't know about after finding something strange was occuring. Personally, if you're a f2p, spending your coupons on this is a bit risky and have a better use for them else where.