She is a ninja featured in the first treasure.

I would say wait for events where you can find her, usually she is in fishing events.

"But I still haven't drawn her".. I know she's in a treasure, but I'm afraid i'll waste 50-100 SS on getting her.

She's only a collectors ninja. Just wait and piece her over time. She's a bad ninja for any kind of pvp or pve, only use is hanzo strong approaching but even there she isnt mandatory as every main (and team) can do that one without problems with free to play setup you can get at lv50 max from elite instances.

Wait till you draw her out of treasure or piece her from events. She isnt worth spending seals on and she mostly good with tendo or pain teams.