"[4 Turns] Catherine infuses her party with the power of rampaging floofballs. Raises ATK a lot."
Cost: 4 
Source: Catherine (starting skill)
Rucklauf ist Vorwarts is a bunny skill that only Catherine can use. Using it grants the party a 2 stage ATK buff for 4 turns.
Trivia
Rucklauf ist Vorwarts, like all of Catherine's moves, is made out of garbled German, which translates to Rewind is forward. Properly, it should be written with umlauts as Rücklauf ist Vorwärts.