Until one day, the friendship ended - Jordan took his own life.
This is when Grace Chong Ho-lan, a student from Christian International School, puts herself in Sean's shoes to write Jordan a letter.
Fortunately, none of this really happened, except in Grace's head. The 15-year-old conjured up the sympathetic plot for Hong Kong's Top Story Awards 2012 - a writing competition co-organised by South China Morning Post and Radio Television Hong Kong.
Grace's tale, written in the form of a letter, topped the junior section of the contest. Her ability to write from the perspective of a young man impressed all the judges.
But in real life Grace radiates a personality completely different to that of her writer's voice - she is a bright, sport-loving girl.
"I'd have to say that my favourite subject is PE," she says. "I was raised in a sort of sport-oriented life, with my dad playing soccer quite often, so I've grown to develop a passion for sports, particularly running and volleyball."
Grace is the captain of her school's volleyball team, which last year won the under-16 division in her district.The young writer came up with her story idea when she was playing volleyball. "Originally, I wanted to write about two girls with cancer," she says. "But many have done it [stories on that theme] already."
And because she was in a training session, she thought: "Why not write about guys?"
Grace only had a few days to finish her story as she found out about the competition just a week before the deadline. Also, she had to deal with homework, tests and projects as the deadline approached.
"I ended up writing at 1am, over a period of three days or so," she says.
Grace enjoys writing at night and finds it more effective. She says it's the time of day when she's free from all the interruptions from her friends and family.
"I tend to write at night, way past midnight, into the early mornings. It just helps me to stay focused," she says. "I just can't seem to be able to write during the day, so pretty much all my short stories and essays for English class have been written [during] the wee hours of the morning."
When asked what she wants to become, the creative side of the young writer kicks in. "This actually changes quite a bit," she says. "Some days, I want to be a potato, a wizard, or a professional fangirl. Other days, I consider sports medicine, becoming a missionary, or a coach."
But it's too little too early for Grace to make up her mind, so she tackles the question with her friend Vanessa's best quote: "Quite frankly my dear, I haven't the strangest clue."
Read Grace's award-winning story, Dear Jordan