在这部海月姬喜剧/爱情片中,本剧改编自东村明子创作的同名漫画，女主角仓下月海（芳根京子 饰）是一名热爱水母的宅女，为了实现成为插画家的梦想而来到了东京。在名为“天水馆”的老旧公寓里，她结识了一群和她一样有着小众爱好且不擅与人交往的御宅族朋友。
某一天，为了拯救一只水母，月海结识了像公主一般闪闪发光的伪娘鲤渊藏之介（濑户康史 饰），于是，宅女与伪娘的故事就此展开……
"Any female can become a princess." Having this as the main moto of the story, a geeky girl called Tsukimi Kurashita who's dream is to become an illustrator one day, moves out to a city, not to attend a vocational school or for work purposes, but simply to chill out in her apartment in her own world. She and her peers feel that society is something that they aren't on par with. In the midst of her life's journey, jellyfish is something that she begins to adore very much, due to some great childhood memories at an aquarium with her mother. When she first saw one, she dreamt that one day she wants to wear a dress just like these species. So, her mother promises her that she will make a wedding dress just for her which looks like a jellyfish. But, her mother suddenly passes away, which allures her into a world of adoration for these species. Eventually, she begins to disregard everything that goes around her, and dedicates her whole life to it. However, her life turns around all of a ...
海月姬，故事的完善丰富之道。创下富士台月九史上最低收视的这部剧，到底做错了什么？。尼姑剧。死宅的日常成长。海月姬。
