For the last two years Zhang has run the most active Chinese social media account devoted to the Foxes, racking up more than 3,000 posts on the Twitter-like Sina Weibo.
When the season began with the team as 5,000-1 outsiders, he had around 3,000 followers. As they stand poised to take the championship, that has more than doubled to over 7,000.
"The team's performance has been extraordinary," Zhang said. "Everyone wants to witness this miracle."
The teenager happened upon Leicester City by chance in 2013 while picking a Premier League team to run while playing the simulation game FIFA Manager.
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When Zhang, a fan of Manchester United goalkeeping great Peter Schmeichel, discovered that his son, Kasper, played for the team, "it was love at first sight".
"I've never left China, but my heart is in Leicester; all along, I've been following the team's developments," he said.
But domestic media outlets carried no reports on his favourite team, and China's strict online censorship regime, which blocks numerous Western news sites and services such as Twitter, left him devoid of information.
"I've been feeling great ever since this season began," he said.
The world's second-largest economy is a crucial market for many of football's biggest teams, who regularly play off-season friendly matches in China.
But until now Leicester has had a decidedly muted presence in China, and set up its own verified Weibo account only two weeks ago.
It has posted fewer than 50 times but has already attracted more than 10,000 followers -- a tiny fraction of Manchester United's 8.6 million or Chelsea's 2.5 million.
Wang Song Aohan, now a 25-year-old communications officer in Beijing, lived just 10 minutes from the King Power Stadium and went every weekend he could.
"Even when they were losing so embarrassingly that I felt even I couldn't watch it any more because it was so painful, I still couldn't avoid being a part of it, and still hoped they'd win," said Wang.
He has met players and coaches, and collected signed jerseys, and while he has supported other teams his relationship with the Foxes is unlike any other.
"When they win, I feel truly happy from the heart; when they score, I go absolutely crazy."
But this season's expected triumph and the associated hordes of new fans jumping on the bandwagon are a bittersweet phenomenon for Wang Beilin.
The 25-year-old, who wants to work in sports management, said she misses the private joy of rooting for the unknown underdog in the world's most populous country.
"Now I feel like they're no longer just my own to cheer for. Suddenly, that's been lost.