Makoto Niwa has just moved from his rural hometown to live with his aunt and experience high school life in the big city first hand. Unfortunately, his dreams of an adolescence filled of dates and school activities are soon shattered by having to share his new home with Erio, his deluded cousin who thinks she’s an alien and spends most of her time wrapped in a futon for protection! Now, in addition to enduring his aunt’s energetic attention and flirting awkwardly with the girls in his class, Makoto finds himself drawn into helping Erio rejoin regular society and stopping her ‘alien’ antics.