Noin is a 15-year-old male with a March 31 birthday and an Aries zodiac sign. He serves as a subordinate to Edward Chi at the White Pegasus Company and is the identical twin of Perch. Physically, he possesses green hair styled in twin tails reaching his chest, brown skin, and blue or green eyes, resulting in an androgynous appearance. A dedicated martial artist, he displays notable combat skills and trains diligently to protect his companions.

Noin and Perch operate as a duo, frequently undertaking missions to obstruct the protagonists' efforts to collect MOParts. While their failures are sometimes comedic, they demonstrate competence during critical battles. Their Motarian forms manifest as animal hybrids—Perch as a polar bear and Noin as a black bear. A significant ability allows them to fuse into a single giant panda form, deployed during the climax against the protagonists.

In the final conflict, Noin and Perch fight alongside Catherine against other Motarians to stall for time while Goro deciphers a crucial tablet. Their fusion into the panda form proves pivotal in battling Taro. Following the resolution, they remain affiliated with White Pegasus, participating in press conferences about new discoveries.