In 1945, the second and third-year students of a Hiroshima girls' school are taken away to work in war factories. The remaining 220 girls of the first year try to make the best of their new-found status as the only teenagers in an almost deserted town, even amid the deprivations of wartime. On the 7th of August, an American bomber changes their lives forever. Broadcast on the 43rd anniversary of Hiroshima in memory of "the girls who lost their lives to the atom bomb."

The story follows Risa, a girl with zero experience in romance. Meanwhile, a boy named Yuugure is the most popular student in Risa's school year. Even though the two have had no contact with each other in the past, they find themselves at school at the same time one night.

The day Lee Joon joins Minsong University to reunite with Kim Margo, his high school crush, he is attacked by his new neighbor Lee Duna, a gorgeous former idol. Violent and impulsive, Duna turns Joon's world upside down. Later, to Joon's confusion, Margo seems incapable of making time to meet with him. To add to his dismay, Joon meets fellow student Choi Ira at a party. She becomes enamored with him after the pair partake in a risqué game. As Joon progressively discovers the truth about Duna's troubled past and Margo's harsh family conditions, he tries to sort out his tangled feelings.

In the future city, science and robots have become necessities in people's lives. The research, development and use of technology maintain a delicate balance between the scientific ethics committee, the technology chaebol, and the third-party security system company Mosh. Wang Xiaoyun, the only son of the Wang Group, was assassinated by an illegal robot while he was out hunting. Everyone in his entourage was spared. The balance of power has been broken, and the undercurrent is surging. Bai Wuxie, captain of the 24th Operation Team in charge of public security, found Zhang Bingyi and Shang Weiyang, consultants who are good at mechanical networks, to assist in the investigation. After several on-site investigations, it was discovered that the murderer turned out to be a product of the "robot oligarchy" Aibozer Company. At the same time, Mosh also encountered a security crisis, and everything seemed to be driven by someone behind the scenes. Zhang Bingyi, Bai Wuxie and Mo Shangshuang from Mosh Company were forced to form a special operations team to find out the truth behind the scenes.