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

He's 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 pleasures. 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 in the end, he will cling to it and never let go. He turns into a yandere stalker. Having never had a partner, his view of romance is slightly warped. He acts spoiled like a baby.