A lonely teen meets a mysterious neighbor who knows his birthday—then vanishes without a trace.

Years later, Suansoon prays for his injured love—then meets his high school–aged self once more.

Onsa and Suansoon grow closer through movies and late-night talks, blurring time and emotion.

As Suansoon moves to a new apartment, he meets another student next door—just like before.

Onsa plans a secret outing for Suansoon as their days together near a quiet, tender end.

Suansoon disappears after leaving Onsa a letter, sparking a desperate and tearful search.

At the theater, Onsa meets Suansoon for the “first” time—two souls crossing through time.

As graduation nears, Onsa and his friends share one last night at Nan’s café before goodbye.

In 2018, Onsa’s accident stirs memories from 2008—where fate links him to the name “Suansoon.”

Onsa reveals his name and leaves a letter for Suansoon as the school’s film night begins.

Suansoon chooses a new path—and a familiar voice answers when he calls about a vacant room.

Reunited at Nan’s café, Suansoon and Onsa finally find peace, love, and the friends they lost.