11633229 Because that is what she is. In the world of Senran Kagura there are Shinobi Schools and Yumi is one of the Elite Shinobi of her school Gessen Girls Academy. She was introduced in the Shinovi Versus game as a rival school that wants to prove its superiority over Hanzo Academy.
This is a Senran Kagura crossover, right?
11633222 Yep, not sure why no one has made one until now.
Why are they calling the protagonist a shinobi?
11633229 Because that is what she is. In the world of Senran Kagura there are Shinobi Schools and Yumi is one of the Elite Shinobi of her school Gessen Girls Academy. She was introduced in the Shinovi Versus game as a rival school that wants to prove its superiority over Hanzo Academy.