Guardian Angel (Osana x Raibaru)

There's been a death at Akademi High!

The bullying hadn't ceased since last week, but Osana was feeling better after some comfort from her friends . It was after class, and Osana was almost ready to leave, when, on time for the bullies, someone walked in.
"Hey," said a voice Osana never heard before. "What's that on your desk? Oh, lemme help you with that." A girl stepped into view. Her stockings were pink at the top, and faded into black. She had three black wristbands on each arm, and the tips of her black hair were bright pink. She had earrings, a base clef in her hair, orange eyes, and black lipstick. "I'm Miyuji Shan, president of the Light Music Club! But we're currently doing rock music! Maybe you'd like to try it?"
"I'm not sure... I've only ever played one instrument..."
"Which one?"
"I play alto sax."
"I'm sure we could incorporate a saxophone! How about you come for one week, and at the end, we'll see if you wanna stay or not."
"Sounds good to me. I'll meet you there!"

At the end of the day, Osana was walking down the hall to go to the Light Music Club when she saw a red substance leading into Taro's classroom.
"Is this blood?" She wondered. She followed it to see it pooled where the teacher would stand, and realized: it wasn't leading in; it was leading out. She texted Miyuji, who'd given Osana her phone number, that she might be late to club activities. She followed it to see a charcoal-haired girl dragging the body of Taro's substitute Mida Rana, who Osana was sure was preying on Taro, to the furnace, and although she was happy to see the pedophile gone, she was frightened. She heard her phone ding, indicating a text, whipped it out, took a photo of the girl, who turned toward her, and ran, texting the police while being chased. "Come on, come on, load already!" When it had finished loading and sent through, she texted Miyuji that she'd seen someone dead and was going to run home, and wasn't gonna make it that day. She felt a hand over her mouth, and saw the blade come to her neck. She had to think fast! She bit her captor's hand, and heard the female grunt of her attacker, most likely the girl who killed Rana. She started frantically texting Raibaru about her situation, and texted her the picture.
"I know that girl! That's Ayano Aishi! She helped me get with you, so I never expected this!" Raibaru texted back. "Come to my house! I'll be waiting."
Osana made it to Raibaru's house, and watched her run out to grab Ayano, karate-chop her arm with the knife, pin her, and break her arm. Osana texted the police to come to 3853878 Hajii Street, where the killer was apprehended.
Fifteen minutes later, the police came and arrested Ayano.
"I helped you get with her, Raibaru! And this is how you repay me? Break my bones and land me in jail?"
"You weren't a murderer when I met you, Aishi!"
After being tried as a minor, the results came: Innocent due to insanity.
"So what now?"
"She'll be under intensive care. She's gonna get better."