Your POV
While I was on my way home from the market to get some groceries for dinner, I saw Killua and a cute girl younger than Killua. Killua was patting her head. They looked really happy together.
Killua's POV
"Onee-chan!" Alluka hugged me tightly. "Keep patting my head!" I giggled a bit. "Okay!" I said. I noticed y/n carrying a couple of bags walking towards me waving.
"Onee-chan, who's that?" Alluka asked curiously. "She's a new friend of mine." I responded. "How's it going Killua?" y/n asked. "I'm doing good." I replied. "Hello there!" y/n said to Alluka.
"What's your name?" y/n asked. "I'm Alluka!" Alluka said cheerfully. "I'm y/n. Nice to meet you!" y/n smiled at Alluka and Alluka smiled back. "Onee-chan! Can I introduce Nanika(Something)?" Alluka asked excitingly. "Okay sure. " I said.
Your POV
Alluka's eyes and mouth turned completely black. "Nanika, this is y/n. "Nice to meet you!" I said smiling. The girl's face turned back to normal. "Alluka's my sister(or brother). Nanika's my sister too. Nanika can grant any wish if you grant her three requests but she barely does that nowadays and I can command her to do anything but I don't like giving her commands." Killua said. "She can grant any wish?" I asked in shock.
"Yea. She helped save Gon when he was in trouble. Oh and I forgot to mention that I'm only staying here for a month because I'm only visiting Gon." Killua said.
"Oh." I said but for some reason I had a horrible, deep, sinking feeling. "I haven't seen him in awhile so that's why I decided to visit him." Killua said. "Well, I'm cooking dinner tonight. Do you guys want to join me?" I asked hoping for a yes. "I wanna go!" Alluka said excitingly. "Okay then. Let's go!" Killua said.
