A Certain Unexplainable Dragon Slayer

The Party

"Y/n, where are you going?" Index asked Esther and Arisa were out for right now and Jason was at his lab so it was just the 2 of them left

"I told you." Y/n sighed. "I'm meeting with a friend who wanted me to come to a birthday party."

"I want to come," Index suddenly demanded.

"Why?" Y/n asked.

"Last Order is my friend." Index pouted. "Also, at birthdays, isn't it traditional to have cake?"

'Ah, that's the real motive.' Y/n sighed again "Well, I suppose you can come, but you have to promise you won't eat all the cake. It is someone else's birthday."

"I promise." said Index, holding up her hand. "I will not eat all the cake."

Y/n eyed her suspiciously because of her lack of argument but then shrugs. He grabs the present he bought for Last Order and they both headed to Accelerator's apartment. Accelerator had sent Y/n his address and told him to be there at 10am.

They left early because Y/n knew, with his luck, they would still be late. They were taking the shortcut through the park when they heard a clang and saw Mikoto kicking the famous vending machine that loved to eat everyone's money. She had just reached down and pulled out a drink.

"Hey Mikoto." Y/n said as they passed.

"Huh?" she jumped and quickly turned around. "What are you doing here?" Her face turned bright red when she saw him. The memory of her conversation with Ruiko was still fresh in her mind and she had not heard him approach.

"Just going to a birthday party," Y/n said then frowned. "Your face is pretty red, are you ok?"

"I'm fine, no problem at all." Mikoto stammered and shook her head and her face slowly became its normal color.

"Hello Short Hair." Index said. Y/n noticed she didn't have a very polite tone.

"I have a name you know." Mikoto replied to her with irritation "It's Mikoto Misaka."

"Short Hair is Short Hair," Index said, shrugging but grinning at the same time

"Well maybe I'll keep calling you Silver Sister then," Mikoto said grinning evilly

"How rude." says Index indignantly. "I have a proper name, it's Index Librorum Prohibitorum."

"Eh," Mikoto said, shrugging and imitating Index. "Silver Sister is Silver Sister." Index got all red and puffed out her chest.

"How rude...." She started to say again.

"Can you two please not fight?" Y/n rubbed his head and sighed. He stepped in between them. "We need to get going, Last Order isn't very patient. She would probably run out looking for us if we are late."

"Wait!" Mikoto said, turning slowly to look at Y/n. "The birthday is for Last Order? She is still being watched by Accelerator, right?"

"Yea, they decided to hold her birthday today since I guess she didn't really have a birth date."

Mikoto slaps her face. "Hang on. I want to get her a present. She is my sister and I want to see how she is doing with that jerk. Wait right here."

"Ah, but," Y/n started to say but it was too late. She already ran off to the nearby stores. "Ah, we are going to be late now." He sighs and sits down on a bench. "Maybe she will be fast."

"Y/n, why are we waiting for Short Hair?" Index asked.

"Because she doesn't know the way and she does have... umm... reasons for seeing Last Order." Y/n said trying to find the right words.