The story begins with the protagonist, Wataru, waking up on the floor of his apartment, hungover and disheveled, surrounded by empty beer cans. He realizes his girlfriend, Natsuki, has left him. A note explains her departure: after four years of waiting for him to propose marriage, she felt lonely and without hope for their future, and has returned to her hometown to consider an arranged marriage. Wataru, consumed by exhaustion from his demanding job at a confectionery manufacturer, "Yamagiri-do," and his own doubts about his future, feels a profound sense of emptiness rather than tears.
The next day, Wataru arrives at work late, still affected by the breakup and hangover. He is called in by his department manager and the manager of the third sales division, Ms. Yamana. He learns he is being transferred to a new, small, elite team focused on sales expansion during the economic downturn, led by Ms. Yamana. Wataru, who had initially aspired to work in product development, feels resigned to being a pawn in the company's family-run structure. He is promoted to section chief, but feels no joy, only the pressure to work harder.
Wataru's sales territory was vast, comprising numerous small shops and businesses he cultivated through persistent door-to-door sales. He struggles with the handover of these accounts to a junior colleague, eventually requiring a third person to assist. He perceives the new project as a hastily conceived idea from upper management.
Ms. Yamana, a seemingly cool and composed beauty, initiates their first meeting by asking Wataru for his ideas. He requests time to think, and they agree to share their ideas the next day. Wataru begins to see Ms. Yamana as less capable than her appearance suggests, perhaps an ornamental figurehead within the Yamana family that controls the company. He starts to develop a somewhat fantastical view of her, questioning if she's even real.
Wataru compiles a list of potential initiatives for the new team, focusing on brand awareness, product lineup expansion, and business model adjustments. Ms. Yamana presents her idea: developing merchandise around the company's mascots, "Yama-san and Kiriri-chan." Wataru finds her idea uninspired and dismisses his own suggestion of using Ms. Yamana as a "beautiful PR representative," though he later adds it to his notes.
The next day, they present their ideas. Wataru explains his proposals, while Ms. Yamana's idea is met with her own self-criticism. Wataru suggests they first decide on a department name. They settle on "Sales Planning Office" and are granted a private office. Ms. Yamana, who appears to be a "spoiled heiress" type, treats Wataru to lunch, revealing her insecurity about her contributions and her past experiences of being overlooked. She also expresses her desire to be more useful.
Wataru begins to see Ms. Yamana as a "troublesome but cute" superior, and their interactions evolve. He helps her with her report, and she buys them matching mugs, suggesting a "two-person team working together." Wataru starts to feel a sense of responsibility for her growth.
The "Sales Planning Office" is established, and Wataru begins working on a project to survey the company's current brand recognition and image. Ms. Yamana, initially focused on creating a department sign, eventually begins working on a report. Wataru proposes a social media and video content strategy, suggesting Ms. Yamana manage the social media accounts and appear in promotional videos. She initially hesitates but agrees to try, seeing it as an opportunity to prove herself. They successfully get approval for the project from management. Ms. Yamana's first tweet is a humorous, self-deprecating message from the restroom, indicating her anxiety. Wataru plans to develop video content, considering ideas like cooking demonstrations and challenges. He proposes a "gourmet challenge" concept where Ms. Yamana would compete in eating contests, which she initially resists but eventually accepts, seeing it as a way to contribute.