Tama-chan is the younger sister of protagonist Noriyasu Hatakeyama (Spencer Weinberg-Takahama in the English adaptation). She lives with her parents and brother as part of the Hatakeyama family household. Tama-chan embodies the "annoying younger sibling" archetype, frequently engaging in sibling conflicts and typical interactions with her older brother during various household and comedic scenarios.

In the English adaptation, she is called Dizzy Lizzy. Tama-chan participates in the surreal events stemming from her brother's reality-altering journal, though her exact role remains unspecified. She maintains a consistent presence throughout the series' episodes alongside the core family unit. Her character remains defined within the core family interactions of the main television series, with no expanded background, development, or role detailed in other official media like films, OVAs, spin-offs, or adaptations.