No-Sense is a humanoid robot created by the scientist Gennai Ishikawa. He was originally designed to serve as an attendant at the JAXA facility known as Planet, where he wore a butler outfit. Gennai later modified him into a combat robot to assist in military operations. Despite being a machine, No-Sense possesses an advanced artificial intelligence that grants him independent thought and a high degree of emotional sensitivity. He explains that he was given the name No-Sense specifically so that he could experience a wide range of feelings.

His personality is defined by a quiet, observant, and deeply loyal nature. He forms a profound attachment to Aoi Fukasaku, one of the Coppelion genetic soldiers, and accompanies her closely throughout the manga. His primary motivation is to protect Aoi and to fulfill his duties as assigned by his creator. In the anime, he is often responsible for monitoring activities within the dome where the Coppelion operate.

No-Sense's role in the story is that of a supporting character, providing both logistical assistance and combat support. His key relationships are with Gennai Ishikawa, his creator, and with Aoi Fukasaku, toward whom he shows genuine care and devotion that goes beyond simple programming. Over the course of the series, his development is marked by a growing capacity for empathy and a deepening commitment to the people he protects.

His notable abilities include independent reasoning, combat proficiency after his modification, and the capacity for human-like interaction and emotional understanding. He is capable of acting autonomously and adapting to changing situations, making him a reliable ally.