When Natsuno Hanabi went back to her hometown to study in high school, she thought that she will have a new wonderful life. But Tachibanakan, the dormitory she was going to live in, was not what she expected.
随着升入高中而回到暌违6年的乡下城镇。从时尚设计风的宿舍“橘馆”优雅地去上学……本来是这么想的，却由于出了差错而沦落到入住破旧公寓“立花馆”的夏乃花火。入住立花馆第一天就遭遇到神秘全裸美少女，偶然目击到年长大姐姐的羞人之处，凝视不知为何与自己针锋相对的青梅竹马的羞人之处。
……完、完全没有觉得“幸运♪”什么的！