Mitsue is snobbish and childish, often using a tone dripping with ridicule or contempt. This superiority complex stems from his elite lineage, wealth, and power. His opulent upbringing, coupled with the intense and often abusive learning sessions about jewels, gems, and crystals, has given him an encyclopedic knowledge in these areas. Furthermore, these sessions may have contributed to his near-photographic memory.

His upbringing also ingrained in him a deep prejudice against other Nyanarr elements and species, considering them inferior. Emotions, except for negative ones like contempt or disgust, are seen as a sign of weakness, a trait to be exploited by the lesser folk.

Born into the affluent Aikawa clan, Mitsue's lineage traces back to ancestors who established a global mining empire. Over generations, the Aikawa family garnered a reputation for their ruthlessness, particularly towards those outside their clan. Valuing the purity of their Light Nyanarr lineage, intermingling with other elements or species is considered sacrilege.

Mitsue grew up apart from his immediate family, living with his Aunt and Uncle after a clan decision distanced him from his older brother, Kioshi. His guardians imposed upon him the identity of their own son and demanded that he forget his past. Their teachings enforced disdain for other species or Nyanarr elements. Mitsue's childhood trauma peaked when he learned about the death of his immediate family in a violent terrorist raid. The tragedy left a void, making him susceptible to the manipulative influence of his Aunt and Uncle.