Yes I know the title is different from the actual story but I'm not a plagiarizer

"Felix! The new neighbors are moving in!"

Felix sighed as he heard Boris's excited voice from downstairs. He was working on an important school project and didn't have time to meet whoever was moving in next door. He put on his headphones and turned on some music so he could focus on his project. He quietly sang along to the tune while writing down the paragraph he needed for school.

When life leaves you high and dry
I'll be at your door tonight
If you need help, if you need help

He thought no one else was nearby, listening to him singing with a smile.

I'll shut down the city lights,
I'll lie, cheat, I'll beg and bribe
To make you well, to make you well

The last line played through his headphones, but the words came from someone else.

He looked around trying to see who else was singing and saw a black cat on his windowsill. He paused his music, taking the headphones off. "Were you the one singing?" He heard a giggle and looked up to see a girl in the tree in his yard, a cat toon like him, but with gray skin and long hair, in a black dress. But those were nothing compared to her eyes.

Heterochromatic, one blue and the other red surrounded by black.

"Pets can't talk, silly! That voice was from none other than yours truly!"
"Oh... You have a nice voice."
"You too, Kittyboy."
"Kittyboy?"

Felix looked confused by the nickname. The girl stretched out her hand for his.

"I'm Shadow. Your new neighbor, friend, comrade, possible love interest."

He reluctantly took her hand in his, earning a bright smile and surprisingly rough handshake.

"I'm Felix. I'm not one to procrastinate when there's a big project due or stay up late when I have school tomorrow, so don't expect any midnight voyages or something."

She pouted.

"Aw, I thought you would totally be the type to rebel with me."
"Yeah, well, I care about school and have to keep my education in gear."

She looked at him for a second before covering her mouth and snickering.

"Smart boy? You thought a pet was singing a few minutes ago!"
"Hey! I didn't even know you existed until now!"

Felix defended himself while Shadow kept laughing. A sharp female voice called her from the house next door and she went sad for a second before putting her smile back on.

"That's my call for dinner, we should talk later."
"Because I'm just the most interesting person ever?"
"Something like that."
"Alright, but no promises I'll be awake."

She giggled a bit.

"Until then, Kittyboy!"
"Until then, Shadow."