Mika Ozawa, affectionately called Mika-chan, serves as the story's central human character. Her ordinary existence fractures when Pen-Pen, a penguin prince from Penguin Land sporting formal attire like a hat and tie, abruptly appears. Without invitation, Pen-Pen introduces himself and promptly invites his eccentric companions to inhabit Mika's home. This unsolicited occupation forms the narrative core, detailing Mika's experience as her domestic space is overtaken by these peculiar guests. The plot revolves around her interactions with the group as they embed themselves into her daily environment.