This was it; It was finally on. The very beginning of her journey in a new world of heroes, one vastly different from anything she had experienced before in the musical industry. It was all kinds of exciting for her and, because she could hardly contain herself and the enthusiasm towards everything related to it, Izu ran at the very forefront of students, although gradually the masses would thin out as they ran into a multitude of directions at different speeds. However, being one of the first people to leave the starting area had its negatives as well. After all when it came to the exercise it was both "First comes first serves" but also a huge risk to rush blindly into the hurdles and dangers that would be thrown at the potential students to test their abilities for the hero course.
As for the aspiring idol-turned-hero, Izu would soon come to face with the first opposition of many; Mechanical canines. Why exactly robot dogs were thrown at her was beyond the girl to figure out. Besides, there was no time to think about such details in the moment anyways.
The blue-haired girl stood opposite of the mechanically growling canine, its sensors fixed upon her frame as she took a defensive stance.
"E-eeek! Robot... dogs..." She said out loud as she mustered her first foe. It managed to stop her dead in her tracks and the both scared and disgusted facial expression of hers made it easy to see just how excited she was that it were canines she was up against, especially after she was already frightened by one earlier today. Spoiler: She was not happy at all to see robo-dogs.
Izu began thinking. "What do I do... what do I do.... hmm... against dogs... and robots?"
But her thinking took too long. The mechanical being lunged at her, a heavy and hostile machinery pouncing at her lik that was really not a pleasant sight, and the idol only managed to escape at the last possible moment by essentially combat-rolling to the side. Now being crouched down after the roll with one knee on the floor, Izu quickly grabbed her backpack from her shoulders and opened it while the canine recovered from the missed attack. "Come on... come on... faster! This should work..."
She opened the bag, grabbed a pen together with a piece of paper and then quickly proceeded to scribble the words "Dog Whistle" onto it. Afterwards she began imagining a very loud beeping noise, one that would make her bones shiver and give her goosebumps if heard by herself. After only a short moment, she held the paper up in full view of the canine and then suddenly, an incredibly loud noise would be played. A noise of such high frequency that it was unable to be heard by humans, luckily. That's right... she played the sound of a Dog Whistle at incredibly high volume!
~Dramatic zoom-in, camera freeze~
Izumo Hatsue - Quirk: Onomatopoeia
By writing down the describtion of a sound while simultaneously thinking about it, Izumo can create any sound which she wants to as long as she herself sufficiently both knows what it sounds like in great detail and can imagine said noise clearly. She can adjust the frequency, pitch and volume of it, allowing her to create sounds which she cannot even hear by shifting the pitch of a sound she is familiar with!
Furthermore, her quirk allows her to visualize any noise that she hears into floating text, visible for anyone, describing the heard sound.