I love your theory so much and it would solidify their love. What Garam needs right now is reassurance from Heejae and that he truly loves him. He needs to know that he loves Garam because it's him rather than his music.
My theory is that they’ll eventually end up in a long-distance relationship, with Garam doing his military service while Heejae is off touring. “Distance makes the heart grow fonder” and all that.
Unless they somehow manage to obtain U.S. citizenship
That's true and hasn't been addressed yet. But, i mean there is also the fact that Garam probably has a green card of sorts to work in the United states ( He works as a pianist). You can become a united states only after 5 years ( been 3 years already) if you have a permanent residence which is at Heejae place. Furthermore, a possibility of marriage with Heejae can officially make him a US citizen.
Was thinking that Garam might eventually obtain U.S. citizenship at 25, but does Heejae hold U.S. citizenship? I dont think theyll be open about their relationship to the public unless they both become U.S. citizens and leave South Korea behind for good, or Garam completes his military service tbh
Heejae is an American born pretty sure since they have a residence in NY or he is a duel citizenship.
According to his Wikipedia page in chapter 2 he was born in Seongnam, Gyeonggi-do, South Korea so I assume hes Korean by nationality, unless he obtained U.S. citizenship, since South Korea generally doesnt recognize dual citizenship.
dropping my theory here so i can say i told ya so!! there is sooo much foreshadowing going on in season 5 that their secret relationship might be made public in season 6! hiding around on tour with compton, discussing their (controversial) age gap, the ghost of the manager still lingering (the author heavily implied the prof might‘ve been in love with the manager and maybe he pushed him away bc he couldn’t accept his feelings then), Garam fearing that the radio station caught wind of theor relationship bc they always play their performances in sequence, and in Ch 205 (mini spoiler) the professor’s former teacher askes him if they plan on keeping their relationship hidden.
dont know if it will hold up for a whole season worth of conflict/tension, but i think it might play a bigger part!
my dream ending for NME would be, that the professor goes full composer mode and keeps on writing music about his love for Garam. Garam keeps being a touring pianist and performs the prof‘s pieces in front of big audiences, therefore ultimately making their love public and letting the music and the performances speak for themselves.
it would also make Garam the ultimate Horowitz to the professor as Rachmaninoff.