A Certain Magical Index Concepts

A Clone is a biological copy of any organic creature. A Clone is mostly created through science and is sometimes abused to an extent.

The practice of dressing like characters from anime, manga, video games, and even novels, TV shows, celebrities, etc.

An esper (or ESP-er) is someone with psychic abilities. The concept is frequently used in a variety of anime series.

Magic is an often used term in fiction. It is the concept of affecting the universe through supernatural methods and breaking the physical laws.