While working at various events, an unknown MC named Kyung Man and his younger sister, Kyung Mi, are taking care of their father, who has been hospitalized for a long time. When he suddenly dies, there is no time to be sad and Kyung Man faces the tough reality of having no money for his father’s funeral. To cover the funeral expenses, Kyung Man secretly goes to the province to work at a birthday party but is gets caught up in an unexpected disturbance there.
Kyung Man has to bless someone else's family to send away his own precious father. Through Kyung Man being forced into a paradoxical situation and his sister having to stay in the funeral hall alone without knowing why, Festival shows how ironic life can be. The burdens and hard work of life are not the same for everyone, but life goes on despite limited understanding and little hope. The constantly changing situation Kyung Man encounters and Kyung Mi's perilous stay at the funeral hall move the suffering relatives them to tears, but through ‘one festival and two funerals,’ the siblings will gradually become stronger and start a new life.
Sung Soo is a successful businessman who lives with his wife Min Ji and their 2 children in a luxury apartment. Life is mostly good, except for an older brother from whom he's estranged.
One day, Sung Soo receives a phone call that his brother is missing and goes to his brother's apartment building for the first time in decades to look for him. There, he finds strange symbols carved into every door and meets Joo Hee and her young daughter. Joo Hee is convinced that someone is spying on them and lives in constant fear. Sung Soo figures out that the symbols carved onto the doors are "hide and seek codes" that indicate gender and number of people. Then when he returns home, he finds similar symbols carved into his door.
Cha Yoon Hee is a successful TV drama producer, who has been afraid of having in-laws, specifically a mother-in-law. Because of this, Yoon Hee has decided to look for a guy who isn't closely connected to his family, and if she couldn't find such a guy, she was planning on staying single.
Finally, Yoon Hee meets Terry, a doctor with a sweet personality who has no recollections of his real parents and was adopted by a couple in America as a young child. Yoon Hee's marriage life seems all set. But her marital bliss is shattered when her husband finds his birth parents and they happen to be her next-door neighbors with whom she bickers on a daily basis, and feature not one, but three sisters-in-law, and the usual array of aunts and in-laws.