If Me and My Sister were in Bungou Stray Dogs

Prologue: Incident Along the Tsurumi River

Roaring filled the ears of a young woman dressed in silver wearing no shoes. A tiger lunged at the woman who dodged skillfully. She chuckled. "I'm afraid it's going to take a lot more to kill me, tiger cub."

Her voice reverberated around the area as she continued dodging. The tiger was getting frustrated and annoyed, the woman was just amused.

When she found herself pinned, the young woman hummed. "Well, this is a curious situation I have found myself in."

The tiger lunged at her. When it got within arms length, it opened it's jaws...

...only to be met by two hands on either side of it's face.

"Selene's Mercy."

The tiger suddenly felt a sense of calm as it landed on it's feet. The young woman didn't look as appetizing anymore. She actually looked quite motherly, something the tiger actually liked. This woman was to be revered, wasn't she?

The woman dressed in silver started stroking the tiger's fur. "There we go. That's a good tiger cub. I hope you feel a lot calmer now."

She continued stroking it's soft fur until she heard her phone ringing from somewhere. She teleported the phone over to her. She answered the phone. "Who is it?"

"Why, hello, Selene! It's been a couple hours! Where are you at?"

"The Tsurumi River. Why do you ask?"

"Make sure to be careful! An eyewitness called us and told us they spotted the tiger! But I honestly think you'd be able to charm the beast. Are you alright?"

"I'm fine. Thank you for asking. Make sure to tell my sister, Osamu."

"Will do! Alright, see you later!"

"Goodbye."

Selene proceeded to hang up before teleporting her phone back to her place. Her left hand had continued stroking the tiger as it purred, happy with the attention it was getting.

Selene was sitting on her knees while the tiger made her lap a place to rest it's head. It was clearly happy with Selene in its vicinity.

Selene then realized which position the moon was in and nudged the tiger. It let out a protesting mewl, making Selene's heart clench. Nonetheless, she rose to her feet. The tiger gave her a curious look. Selene kissed its nose. "My apologies, tiger cub, but I have to leave now. I can't stay with you forever."

The tiger let out a whiny mewl, not at all happy with her leaving. Selene pursed her lips. "I'm not happy either, but I must. Don't worry, I promise to see you soon, cub. Goodbye."

Selene proceeded to teleport away. The tiger, now alone, let out a series of cries and whines at being left alone before getting up.

It was time to continue roaming.

...

Alexandria was waiting patiently for her sister to come home anxiously. Dazai had called her and alleviated some of her worries, but the thought of her sister being near a beast was enough to send a shudder down her spine.

When her sister opened the door while fiddling with her owl totem necklace, Lexi threw herself into her sister's arms. "Cecelia! Oh thank goodness you're home!"

Cecelia stumbled a tab before pushing herself inside and closing the door. "I'm sorry to worry you, imouto. I merely ran into a lone beast."

"A lone beast-! You surprise me sometimes."

"Good. It keeps things interesting."

The two stayed in the silence before Cecelia spoke up again. "The tiger is an ability user. A poorly trained one, but an ability user nonetheless."

Lexi gave her sister a confused look. "What makes you say that?"

"Before I saw the tiger, I saw a young man. He seemed like he was starving and his clothes were quite poorly. I then saw his body mutate and turn into the tiger. I didn't see his features clearly, but I could just tell it was a man."

"If that's what you say, big sis..."

Cecelia glanced out her window at the new dawn that was coming. Maybe she'd ask Dazai and Kunikida if she could aid them with their little tiger hunt.

After all, she was sure she was right.