Jiang Mina (Choi Kang-hee), a civil servant in the Gyeonggi-do Taxation Department, works hard and is upright, but she was suspended for two months because of an impulse. At the same time, her fiancé also exposed his unreliable character, which made her break up in anger. Her father in her hometown was hospitalized due to illness and handed over the stationery store he had run for a lifetime to her. During the suspension period, Mina also happened to have time to watch the store and handle inventory. This Mina stationery store located at the gate of Guilin Primary School once made Mina suffer a lot of grievances in her childhood, and she just wanted to sell the store as soon as possible. On the other hand, Mina’s former classmate, Cui Qianghao (Bong Tae-gyu), who also graduated from Guilin Primary School, returned to his alma mater as a teacher. The experience of being ignored in the past made Cui Qianghao take good care of each of his students, while Mina was in the noisy sea of children and tried to clear the goods. Gradually, the personal experience in the store made Mina understand her father's thoughts...