Kaoru is a 29-year-old corporate drone living in a run-down apartment, nearing his thirties. His age equals the number of years he's been single, and he sarcastically mutters to himself daily, "I might actually become a legendary wizard at this rate." At work, he's unfairly berated by his boss and looked down upon by his subordinates. When he finally drags himself home, the "sweet sounds" from room 202 next door interfere with his rest.

He is semi-depressed and emotionally unstable. Shrouded in a negative aura, he always looks exhausted with deep dark circles under his eyes. Alcohol and cigarettes are his only solace. When he gets too drunk, he wails and laments his lot in life. However, he only vents his bitterness and never actually takes action.

If a healing hand is extended to him, he will be extremely wary at first. But eventually, he will cling to it and never let go, turning into a yandere stalker. Having never had a partner, his view of romance is somewhat warped. He will act spoiled like a baby.