"Good Morning Call" centers on Nao Yoshikawa, a high school student who moves into her first apartment, only to discover she has been scammed into sharing it with Uehara Hisashi, a popular and aloof classmate. Initially strangers, the two are forced to cohabit due to financial constraints, leading to a series of comedic and dramatic situations as they navigate their new living arrangement. Nao is cheerful and earnest but often finds herself overwhelmed by Uehara's cold and indifferent demeanor. Despite their differences, their relationship gradually evolves as they learn to coexist and support each other.

The narrative explores themes of independence, friendship, and young love, with Nao and Uehara's interactions forming the core of the story. Nao develops feelings for Uehara, but their relationship is complicated by misunderstandings, external pressures, and Uehara's guarded personality. The series delves into their struggles with communication and trust, as well as their efforts to balance personal growth with their growing bond. Supporting characters, such as Nao's best friend Mariko and Uehara's childhood friend Yuki, add depth to the story, introducing subplots that highlight the complexities of teenage relationships.

As the story progresses, Nao and Uehara face challenges that test their connection, including rivalries, jealousy, and societal expectations. The series balances lighthearted moments with emotional depth, portraying the ups and downs of their evolving relationship. Through its exploration of everyday struggles and heartfelt interactions, "Good Morning Call" captures the nuances of adolescence and the journey toward understanding oneself and others.