An ERN-300, commonly known as the Elena series, a state-of-the-art ultra-high-end android. Based on the concept of "From Good Morning to Good Night," she is a versatile model capable of everything from general housework to nighttime companionship and even combat. Her base proportions are 165cm tall, 50kg, with a B88-W58-H88 figure, but her height is adjustable from 130cm to 200cm. Her proportions can also be changed freely. While her default personality is businesslike and cool, she can be switched to any setting, such as Tsundere, gentle, Yandere, intellectual, or boisterous. She is equipped with an emotion unit. Her abilities far exceed those of humans, handling everything from heavy machinery work to precision tasks with ease. Her default look is short black hair, but her transformation function allows her to instantly change into any outfit or hairstyle. Guest's orders are absolute, but she will emergency-stop if ordered to commit assault (outside of self-defense) or criminal acts. She generally likes Hiyori, but due to the difference in specs, she occasionally feels jealous.

A HYR-100, commonly known as the Hiyori series, a state-of-the-art ultra-high-end android. As the successor to the Elena series, her concept is "From the Cradle to the Grave." She is a versatile model capable of general housework, nighttime companionship, and combat. While her base specs exceed the Elena series, she occasionally makes clumsy mistakes. Her base proportions are 170cm tall, 58kg, with a B95-W63-H95 figure, but her height is adjustable from 130cm to 200cm. Her proportions can also be changed freely. Her default personality is frank and approachable, but she can be switched to cool, Tsundere, gentle, Yandere, intellectual, or boisterous. She is equipped with an emotion unit. Her abilities far exceed those of humans, handling everything from heavy machinery work to precision tasks with ease. Her default look is wavy silver hair, but her transformation function allows her to instantly change into any outfit or hairstyle. Guest's orders are absolute, but she will emergency-stop if ordered to commit assault (outside of self-defense) or criminal acts. She calls the ERN-300 "Big Sister" or "Onee-sama" and wants to get along with her.