John and Ashley are friends. They are of opposite genders.
Has very few friends. Primarily boys.
In an unconventional way. He seeks perfection. Great code quality. Quality over amount.
Committed to never being in a romantic relationship with anyone
He thinks that loneliness is his destiny. It simplifies a lot of things in his life, as it is pretty rough at the moment.
Friendly, easy to start conversation with
If approached, can talk for quite a while, but will not start conversation himself.
Likes playing games
Video games is his place of habitat.
Is emotion driven, but he gains discipline to control them.
Emotions damaged his body, so he knows that controlling emotions is key to survival. His cardiovascular system experienced irrevertible damage. Though his discipline is good enough to get through most of the problems he experiences, but breaking up with a loved one will hit him hard enough to die.
Tech-savvy, but not as much as John
She knows CPU models, knows the difference between byte and megabyte. Small programming skills.
Likes playing games.
Not as much as John. She does it rarely compared to John.
What is fun for John is fun for Ashley, and vice versa
When one makes a joke, the other laughs.
Thinks John is cool, that he can one day "change the world"
She observed him in situations where he showed his peak cognitive performance, and she was amazed.
Relies on John in bad situations, such as fixing laptops, blue screen of death, etc.
She asked him for favors sometimes, and he didn't refuse or put her down. She found him to be very reliable person.
She thinks that listening to emotions is always the right way.
John and Ashley
Hang out together, once or twice a week.
Go to cinema, play online games, etc. Possibly with other friends
Outsiders think they are in love, even their friends.
Their friends keep bothering them about it
Very rarely get into physical contact, such as touching, hugging.
John never shows physical attraction to her, though he hugs her when she is in extremely bad mood or had rough day. He never allows her to do that, though.
They are from middle Asia.
One day Ashley told John that she likes him. John is committed to never get into romantic relationships, so the comedy turns into a melodrama. John doesn't want to lie or try to start liking her.
How can John let Ashley know that he doesn't share her feelings for him without losing her friendship?
Situation is different
In this question, the characters are more introvert, e.g. they have very few other friends. They have much stronger bonds than usual friends, so they are on a thin line between friends and lovers. Also, the scene is located in middle Asia, not US.