Katsuma means 'Action', and refers to the law of cause and effect.
The concept of katsuma encapsulates the understanding that every thought, word, action, or experience (i.e. reaction / response to situation, circumstance or events,) no matter how seemingly small or insignificant, will have consequences - be they beneficial or otherwise. Katsuma speaks to us of the power latent within action - of the power and importance of thought, word & action - & also encourages us to be mindful of the probable outcomes resulting from our actions.

Or its a play monster on 'moshi monsters'