Rita grew up with Leo since childhood, but Rita was adopted to the Netherlands and Leo to the USA. There, they were injected with killing techniques and worked as assassins. Now, Rita is at the kindergarten and Leo is part of the New World Order, making them enemies.

Originally from Las Vegas, Doug collected money through various scams until he was caught by the police and sent to the kindergarten.

Hana comes from a long line of assassins and grew up under her father's abuse alongside Sho Bradley. While working as an assassin, she was caught by the police and came to the kindergarten. She killed her father with Rita and Doug, and her brother turned himself in.

Her real name is Laurel Scott, but no one knows. While working as a transporter, she had an older sister (Silvia Scott) who died in a car accident. She was caught by the police and came to the kindergarten.

A former British police officer. He had a lover named Tina, but when they were in danger of being killed by his superiors, he killed all of them. When he hesitated to kill one senior officer, the senior fired at Luke, and Tina took the bullet and died. He was then caught and sent to the kindergarten.