SwagAge: Shout Out, Joseon! is set in a fictional kingdom where sijo poetry has been banned for 15 years. The prohibition was imposed by Hongguk, the powerful Minister of Sijo, who murdered the former king and rules through a young monarch with little authority.

Dan, an orphan rejected by society, openly sings sijo in the marketplace despite the ban. He later discovers that Gukbonggwan, a secret performance club operated by Hongguk’s daughter Jin, is the headquarters of Golbindang, an underground group using poetry and music to speak for the people.

Golbindang’s leader Shipjoo recognizes Dan as the son of Jamo, a commoner who once defeated the aristocratic Hongguk to become Minister of Sijo. Hongguk falsely accused Jamo of treason, arranged his exile, and had him killed. After learning the truth about his father, Dan joins Golbindang.

Hoping to hear the voices of his people, the young king announces the first National Sijo Competition since the ban. Hongguk allows the event only because he intends to expose Dan’s identity and destroy Golbindang. The group reaches the final and performs songs about war, poverty, injustice, and the suffering hidden from the court. Their performance begins to awaken the king, but Hongguk arrests them as rebels and tortures Shipjoo.

Jono, Hongguk’s enforcer, turns against him and helps Golbindang escape. He gives Jin documents proving that Hongguk framed Jamo and arranged the former king’s assassination, then dies protecting the group.

Dan and Golbindang present the evidence before the king. Hongguk is stripped of power, branded, and exiled. When the king offers Dan a reward, Dan asks only that every person in Joseon be allowed to sing sijo freely.