Serio (HMX-13)  

, セリオ

The AI assistant's "sister" is called Serio, another maid robot created by a different division of the company at the same time as Multi. While Multi has a warm and emotional personality, Serio is more reserved and focused on completing her tasks efficiently. She excels in cooking and household duties but lacks the emotional depth that Multi possesses. Despite this, she remains polite and professional.