Series by 赤松健

Keitaro Urashima, a ronin who has failed the University of Tokyo entrance exam twice, gets kicked out of his house and heads to his grandmother's hot spring inn for a place to stay and continue studying. Upon arrival, he discovers the inn has become an all-girls dormitory where men are strictly prohibited, leading to immediate chaos when he accidentally intrudes on the residents. After a misunderstanding where he pretends to be a Tokyo University student to gain entry, his grandmother appoints him as the dormitory manager, forcing him to live among the female tenants despite their initial resistance. He meets Naru Narusegawa, a top-scoring high school girl living there who excels in studies and reluctantly begins helping him with his exam preparation after repeated encounters. The household includes other residents like the shy Shinobu Maehara, the sword-wielding Motoko Aoyama, the energetic Kaolla Su, and the laid-back Mitsune Konno, all of whom interact with Keitaro through comedic mishaps and daily dormitory life as he pursues his long-held promise to enter the university with a girl from his childhood.

Kobe Hitoshi is a 16-year-old high schooler with zero luck in studies, sports, or romance, constantly teased by classmates and feeling like life’s punching bag. His one shining talent is computer programming, and he’s crafted an artificial intelligence named Number 30—Saati for short—designed to be his dream girlfriend. One stormy day, a lightning strike zaps Saati into the real world, kicking off their chaotic life together.