The Firefighter Card is a level 10 water power card in Card-Jitsu and Card-Jitsu Fire. It can be the power card you get with your Starter Deck. It shows a fire-penguin (the penguin variation of fire-fighters) trying to put out a flaming black puffle.
The card scorer becomes a firefighter and sprays the opponent. When this is played lower values win the next round. That basically means that this effect contradicts the rules because if the elements are the same with this effect, the lower card will win. This is probably why half the starter cards are 2's and 3's.