>>14253154It's one of those particles you put at the end of a sentence for emphasis. Typically women use "wa", "wa yo", "wa ne", "no ne", or "no yo", while men use "da", "kai", "sa", "yo", "ze" or "zo".
Basically, it means Marisa talks like a guy. And not in the way you usually see in anime, where a character uses a more masculine word for "I" than normal; Marisa still refers to herself as "watashi", her language is just really casual and slightly rough. This is usually translated by giving her a Texas accent.