Ichiko is a supporting character, known as one of the Zashiki-warashi twins who reside within the nursery of the Japanese Hell. Her presence brings a gentle and peaceful atmosphere to her surroundings, offering a stark contrast to the typically chaotic environment of the afterlife.

In terms of personality, Ichiko is characterized by her polite and quiet demeanor. She often appears reserved and soft-spoken, embodying a sense of innocence and tranquility. Her primary motivation and role in the story involve her responsibility of comforting the souls of deceased children who come to the nursery, providing them with solace and care during their difficult transition. This makes her a beloved figure not only among the young souls but also among the staff and other residents of Hell.

A key relationship in her life is with her twin sister, Niko, with whom she shares the duty of maintaining the nursery's calm environment. While specific details regarding her personal development throughout the series are not extensively documented, her consistent nature serves as a stable and reassuring presence. Her notable abilities are tied to her identity as a Zashiki-warashi, a benevolent spirit known to bring good fortune, though her primary displayed strength is her inherent talent for creating a soothing and peaceful ambiance in a typically harsh realm.