Training Revenge

Sorry, I am really bad at summaries but... I'll try.
Masako is a seventeen year old girl who has been training to be an assassin. Her goal is to take revenge against her mother's murderer and finally live her life without feeling the weight of the incident.
And now I'll give you an excerpt to give you a sense of my writing style:

"Come on, get into a line and give it a try". Slowly people formed one, hesitant, not wanting to fail. Masako glided over with confidence as the cool metal of the blade balanced within her fingertips. With expert precision, the knife flew out of her grasp, the satisfactory THUNK of the knife sticking in the bullseye of the dummy's stomach echoed through the room.
A smirk broke out over Masako's lips as she dusted off her hands and strode to the back of the line once more. "Wow Masako, that was amazing" Shay gushed. "I didn't even hit the target" she mumbled.
"You'll get there with practice, all these punishment exercises will help too. I've been here since I was seven years old Shay, that's ten years of experience in all this training. You've only been here since you were what, twelve? That's only three years, you'll get there" Masako lectured the younger girl, watching her other classmates take turns at the knife station.