Fantasy Boys is a global boy band project where 54 boys compete to become members of a new boy band; the boys will be divided into three groups based on their grades.

After the boys' grades are decided, they receive their first theme song; they must master it to be able to either secure their place or advance; the most desperate ones are the boys in grade three as only five of them will be granted entrance.

Producer Woo-young visits the boys to announce the second semester's mission, Visual Mission; the boys choose the themes of their choice among six different costumes and they're given mission songs.

The boys are divided into six teams according to the costumes they've chosen; as they prepare for the performance, some boys show their passion while some of them struggle as they feel pressure; however, the boys are ready to show off their charms.

The second semester's final results are revealed and five are eliminated; in the third semester, the boys choose their positions and compete as teams.

The Major Field Mission performances are revealed; the teams' struggles and successes are shown through practice sessions and performances; which team will secure the individual and team benefits?