距离与维克特路基艾尔的决战已经过了一年，光（根岸拓哉 饰）结束了一年的海外进修，回到了日本。此时，咲夜（小池里奈饰）和玛娜（最上もが饰）也一起加入了UPG，组成了新生UPG。
这个女孩名叫吉山智本（铃木春树配音），她的真实身份实际上是住在106号房间的一个鬼魂。在吓跑小太郎的计划失败后，Hayao逐渐习惯了和他一起生活。Hayao并不是唯一一个想和Kotaro竞争房间的人。来自遥远外太空的文明晚期后裔黑野基里华（田泽多摩配音）、出乎意料的魔法女孩红野由里香（小森里也配音）和皇室女儿蒂亚·米斯林（长绳玛利亚配音）的火热身影，所有这些相继出现的美丽女孩，每个人都让106号房间成为了侵略的目标。为了保护他赖以生存的廉价租赁住房，小太郎的“战争”开始了。
The woman next door; She became my exclusive special advisor. I will teach you the real skills to inspire women's enthusiasm! The so-called theoretical expert Seong jin only understands women through text, and whenever he sees his academic advisor Professor Mi ae, he feels excited. However, Meiai ignored his courtship and told him to come back when he grew up. He felt helpless and finally revealed his pain to the novelist Yang Hua who had recently moved next door. To his surprise, she said she would teach him about women and start coaching him on real-life courses from kissing to sex.
