Cha Young-mi is a young woman who has lost her parents and struggles to fend for herself. A mysterious stranger begins stepping in, paying her university fees and sending thoughtful gifts, and Young-mi affectionately nicknames this generous donor Daddy-Long-Legs. The kindness feels steady and almost ethereal, as if someone unseen is quietly shaping the course of her life. The benefactor behind the generosity is Hyung-joon, a figure whose presence lingers in her memories even as his identity remains shrouded.
After finishing her studies and facing early career hurdles, Young-mi lands her dream job as a program writer at a nationally syndicated radio station. She also secures a rent-free hamper of good fortune: a comfortable house left vacant by its owner for health reasons. Believing that these blessings come from her benevolent guardian, Young-mi clings to the feeling of being watched over by her mystery benefactor, the enduring echo of Daddy-Long-Legs guiding her forward.
Then a peculiar email arrives at the house—dated for that day but written a year earlier. The message reveals a love story written by the unseen house owner: a girl who fell for a boy in school, followed him into the same college program, and later into a radio job. The girl learns she is diagnosed with a terminal illness that will erase her memory, and so she crafts the email to reach herself in the future in order not to forget. The revelation unsettles Young-mi, but it also sets a plan in motion: she decides to broadcast the email’s contents on the national radio program, turning the tale into a serialized, dramatized feature in hopes of locating the man who inspired it. The response from listeners is swift and ardent, and the airwaves ignite with curiosity, longing, and the mystery of memory.
As the story unfolds on the air, Young-mi meets Kim Joon-ho, who works as a librarian at the station. They spend time together, and Young-mi begins to fall for him, drawn by their shared moments and a growing sense of intimacy. Yet the more she digs into the email’s origin, the more she discovers that Jun-ho is the very man the writer spoke of—and that he is tied to the quiet, past-tense romance being broadcast. The emotional conflict deepens as she wrestles with the knowledge that someone somewhere has carried a secret love for years.
Her investigation reveals a deeper, almost fated twist: the director of the station had arranged Young-mi’s current job and housing, acting on behalf of his younger brother, who is the writer of the email. That younger brother, Jun-ho, had switched genders when writing the note and had lost memories of Young-mi from their school days; when their paths finally cross in the station’s library, it is the first true meeting for both of them. The discovery shakes Young-mi to her core, complicating her affections and sense of trust.
Devastated but unresolved, Young-mi confronts the tangled web of connections that brought her to this moment. She reconnects with Jun-ho, and they share time together as their bond deepens, even as his illness relapses. In the end, Jun-ho’s health falters and he dies, leaving Young-mi to reflect on memory, love, and the uncertain mercy of fate.
