Butterfly swimmer Hang-yu, 23, is taking a part-time degree course offered by the Beijing Sports University at Hong Kong Sports Institute.
Backstroke swimmer Henry, 18, and butterfly star Derick, 16 are both secondary school students. Henry is a sixth-former at Diocesan Boys' School but he is planning to go overseas this summer to further his studies. Derick, a Form Five student at St Joseph's College, will take the HKDSE exam next year.
Yet, in the pool, they will all focus on just one prize - a place at the 2012 Olympic Games in London.
They know the road ahead won't be easy.
"Each country or region can send not more than two swimmers for each event," Hang-yu says. "Swimmers now have to reach a faster Olympic qualifying time to book their place. Those who achieve the slower Olympic invitation time are not guaranteed a spot."
Hang-yu tried hard to qualify for the 2008 Beijing Games but failed.
"In every race I was just 0.2 or 0.3 second slower than the required time and the failures made me so depressed that I considered retirement," she says.
Luckily Hang-yu didn't give up and before long she was back to her best. Hang-yu was superb at the 2009 East Asian Games, where the two boys also put in some eye-catching performances.
"Before the Games, people ignored the boys' efforts because it was very hard for us to win medals at major multi-sports events. The East Asian Games made me a star in school," says Derick.
Henry may leave for the United States this summer but he says he hopes to strike a good balance between studies and sport. "Swimming has broadened my horizons," he says. "I have been to many countries and I have learned a lot from top swimmers. And swimming can help me stay healthy."
Derick is facing a dilemma because the final Olympic qualifiers coincide with next year's HKDSE exam which will be held in March and April.
He says the exam is also important so he will seek advice from his coach and parents.
But, for now, nothing will stop the boys from trying to make their dream come true.
Derick and Henry, along with their "big sister" Hang-yu, will head to Spain later this month to take part in their first qualifying event for the London Olympics.
Hang-yu is not afraid of failure this time. "I have already forgotten about last time. It is just like an exam in school. If you fail a subject, would you quit your studies immediately? Even if we can't make it to the London Games, we still have the World Championships, Asian Games, East Asian Games, and so on. There is always a target," she says.
As for the boys, they are looking far ahead. "We can always aim for the Rio de Janerio Games [in Brazil] in 2016," they say.