Souta Tachibana is an unremarkable young man coasting through life, notable only for his very short stature. His routine is upended when his older sister, Kaori, conscripts him into a new role as the live-in dorm manager and coach for her universitys womens volleyball team. Suddenly finding himself as the lone man in a residence of tall, athletic, and assertive women, Sota becomes the unexpected center of attention.

The story is set primarily at Hokuei University, within the teams dormitory and gymnasium, where Sota must navigate his chaotic new life. The situation is further complicated by a fateful reunion with Ayano Hasegawa, his first love, who is now one of the teams players. As he attempts to figure out which of the big girls he might want to pursue a relationship with, he must also contend with the physical and comedic perils of being surrounded by women who literally tower over him.

The main cast includes the diminutive protagonist Souta Tachibana; his scheming sister Kaori; his childhood crush Ayano Hasegawa; and other team members like the teasing Sanae Yamada, the strict Kyoka Teshigawara, and the foreign player Julia Mackenzie. Throughout the series, notable narrative arcs include Souta being forced to manage a new, troublesome player named Momomi who joins the team, and a storyline where Kaori falls into a volleyball slump, prompting Sanae to order Souta and Kaori on a date to an old childhood sauna to resolve it.