So today's card's name appears to have come straight from the Bandai Battle Spirits Flavor Text Translation Department HQ.
Honestly... "Water Pistol?" Really? Well, I guess Gamatatsu is pretty pathetic...
Luckily, the card itself is better than the name and I see this as inheriting Paper Bomb's spot in an aggressive Lightning deck with Toads (not the combo Gamabunta one, although it certainly could fit in there as well). There certainly is some sick blowout potential with the card - opponent looks to chump block with a team slightly smaller than your own, you Pistol their 2/3 Hinata out of their team, and all of a sudden it's a pseudo-OV (assuming you've got the combination ninja).
Of course, that's the optimal situation - this card has plenty of other uses. Obviously, it can be used to push for BRs (as well as killing an injured chump blocker, significantly reducing the value the opponent thought they would be getting out of it). It can be used as a pseudo-Wind Scythe for negation purposes (that could possibly be more devastating depending on how the battling teams are arranged).
However, all this depends on if more good early game (T3 and less) ninja toads are printed. The 4/0 0 drop and 0/2 1 drop are perfectly legit to play. The reprinted 0/0 one is highly suspect in anything but a Gamabunta deck (although I am a fan of dropping Giant Ninja Toads into play on turn 2). With only 2 outs for actually playing this card, it's not particularly viable as it can't be reliably played in the early game. If Bandai were to print 2 or more early game ninja toads, this card could be a staple of the post-rotation metagame.