The great adventures of life and human connections in contemporary Korean society, following a formal baseball player, a sleepless student, a new hangman, an imprisoned gangster, and a mysterious father and daughter.

Su-kyung is a young adult who is struggling to fit in at work due to her introverted nature. She signs up for an SNS service, where she begins to communicate regularly with a stranger named Jeong-yeon. Having no other friend, Su-kyung opens up to Jeong-yeon, and the two of them finally agree to meet up in person.

Haneul has taken the next step in her life after leaving the orphanage, and moved into her new home. Suddenly, she wakes up, noticing that all her belongings are gone! She now goes on an adventure to reclaim her lost home and learn the true meaning of self-reliance.

Jimin and Hyunsang hold their poetry club meeting in the park. Whether driven by the poem's content or by their increasingly discordant feelings, the two start behaving strangely.

Professor Se-jeong is thrust into a bloody nightmare when a rapidly mutating virus is released during a biotech conference causing authorities to seal the facility. Trapped inside with no escape, Se-jeong along with a small group of survivors must fight to stay alive while the infected undergo horrific transformations.