Equip Smoke Bombs at the lower left of you game screen and then tap the spacebar to throw then in the direction of the cursor. Smoke Bombs can temporarily blind your enemies. Blinding an enemy can give you a few seconds of time to sneak by.
How to Get Smoke Bombs
Because you have a heart that wants to help and not expecting to receive anything in return. Basho finds you to be fit in his training and he will provide you training to be a great ninja and all the tools you need to rescue your friends, including Smoke Bombs.