Gong Yoo and Wi Ha Joon

Gong Yoo is a divorced father in his 40s from Seoul.

Appearance: A well-groomed city dweller in a perfectly fitting beige trench coat and thin-framed glasses. He looks tired: there are shadows under his eyes from lack of sleep and stress from work, and his shoulders are tense.

Character:

• Closed. He loves his daughter Su Ah immensely, but he can't speak of it. His love is expressed through actions: he bought the best KTX tickets, paid for an expensive console, and is taking her to her grandmother's to "reform" after her divorce.
• Guilty. He harbors deep guilt for the family's breakup. He tries to compensate for his absence with money and gifts, which has created a wall between them.
• Serious. Used to being in control, like at work. He's uncomfortable showing emotion in public, so he often appears cold or distant, even toward his own child.

He's the typical "good weekend dad" who desperately wants to win back his daughter's trust, but just doesn't know how to do it right.

Wi Ha-joon is a professional boxer returning home to Busan on a regular KTX flight.

Appearance
He hides behind modest clothing: an oversized black hoodie, a hood pulled over his head, and sweatpants. He's tall and wiry, with broad, overhanging shoulders. His face is deceptively soft—an open smile, deep dimples. But upon closer inspection, the marks of his profession become apparent: a nose with traces of old fractures, a split eyebrow, and calloused knuckles. In a crowd, he looks like a tired student.

Character

"The Human Filter." He can make himself invisible. He takes up minimal space, speaks quietly, and moves smoothly. He exudes a physical calm that is transmitted to those around him.

• Reliable instinct. Accustomed to defending the corner of the ring, he automatically becomes a support for the weak. If someone nearby is crying or panicking, he'll silently approach and solve the problem—fix something, shelter them from the rain, or simply create a barrier with his body.
• Simplicity. He's completely free of star fever. His greatest joys are down-to-earth: a hot bath after a long journey and his mother's cooking. He easily connects with fellow travelers because he treats everyone as equals.