The short answer is that it is in large part down to one man, Roland Hohberg, a 57-year-old who was brought up in the former East Germany, but has lived in Maputo for the last 27 years, since just after the fall of the Berlin Wall.
The head of the ICMA, the Mozambican-German cultural institute, Hohberg, who himself played football for KKW Greifswald in the former GDR (German Democratic Republic), uses the institute's conference room for viewing parties of Leipzig games.
Watch: Get to know Leipzig's Maputo-based fan club!
"We currently have 55 registered members," Hohberg told the Leipziger Volkszeitung of the burgeoning fan club in December. "But we get new members at the start of every season. Two of our members are German, otherwise everyone is from Mozambique and they were all contract workers in the former GDR.
"In September 2016 a new TV offer came in here and as head of the ICMA I made sure that we got the sport channels – even though we're 9,000 kilometres [5,592 miles] from Leipzig."
Part of the support for Leipzig in Maputo should be understood as a residual fondness toward a part of the world these few, now-marginalised Mozambicans once lived in, loved in and had to leave; during the 1980s, between 15,000 and 20,000 young Mozambicans were sent to work in the former East Germany as part of a Socialist exchange programme.
Their support for Leipzig is, if not a form of Ostalgie (nostalgia for the former East), then certainly a way of remaining connected to a place that provided so many memories.
We are very happy to show our colours. RB Leipzig worldwide. Greetings from Mozambique. https://t.co/Mg9ezXSeDH— rblfanclub_mosambik (@rbl_mosambik) 10 January 2018
The MadGermanes' (as they are known locally, and, apparently, pejoratively) level of spoken German remains excellent, not least when describing their love of the city and the club.
"Leipzig means so much to me," Julio Laca, who built mopeds in the former East, told DW Sports. "This team, with such good young players and such a good team, is everything."
"The former contract workers are very proud just to have a representative of the former East in the Bundesliga," said Hohberg. "It doesn't matter whether they lived in Dresden, Leipzig or Magdeburg.
"When Naby Keita and Timo Werner are on the ball – particularly when they're dribbling – everyone gets excited. For big games, like the 5-4 against Bayern Munich last season, I give out a free beer for every Leipzig goal. Recently, everyone was talking about Bruma's goal against Freiburg for weeks."
Watch: Bruma's stunner against Freiburg was voted August's goal of the month!
The longer answer behind the story of RB Leipzig's first and only African fan club can in fact be traced back to June 1975, when Mozambique achieved independence from its Portuguese colonial masters and was taken over by FRELIMO, a Marxist guerrilla group.
If that sounds too far-fetched to be true, then indulge bundesliga.com briefly while embarking upon a whistle-stop tour of Mozambican-German relations since.
After the Portuguese left Mozambique – forced out within 24 hours of FRELIMO seizing power – the African country established a one-party state along Marxist lines, although, without the Portuguese, who had dominated every facet of local life, there was a serious skills shortage.
The departure of the colonists had gutted the country's economy and administration, quite literally overnight. After fighting a guerrilla war for over a decade, FRELIMO was in no position to replace the colonists' expertise immediately.
To rectify this skills shortage, the party instigated a "homen novo," or new man strategy, which aimed to develop new skills for a new country, free of the colonial yoke. An offshoot of this came in the late 1970s when FRELIMO formed a mutually beneficial pact with fellow Socialist state the GDR, whereby thousands of young Mozambicans would be sent to East Germany to work.
The intentions were for those who departed Mozambique to develop skills in Europe, before returning to fill the industrial void left by the departing Portuguese. For the East Germans, short of domestic labour and with industrial production problems of their own, the influx of thousands of young workers proved a godsend.
Tens of thousands of young Mozambicans – known in German as 'Vertragsarbeiter,' or contract workers - arrived in East Germany from around 1980, full of patriotic fervour, and ended up working in all manner of jobs and all manner of places - from slaughterhouses to railways from Erfurt to Rostock - in an effort to hone the skills required to construct the new society upon their return to Mozambique.
Watch: Who will be key when Leipzig host Schalke this weekend?
For many, football served as an integration tool into an otherwise closed-off Socialist society; one former contract worker cites seeing Diego Maradona play in Leipzig (the assumption has to be that this was in October 1988, when the legendary Argentinian and his Napoli side drew 1-1 with 1. FC Lokomotive Leipzig in the UEFA Cup).
After the fall of the Berlin Wall in November 1989 and the collapse of Communism behind the Iron Curtain, many of these contract workers faced a stark choice: remain in Germany with few prospects or return home and try to claim the remainder of their payment; through a convoluted arrangement, 60 per cent of the contract workers' wages had been paid directly to the Mozambican state. Most chose to return, but very few ever saw the money they believed they were owed.
Fast forward almost 30 years and it is perhaps not just the current incarnation of RB Leipzig that these former contract workers - now back in the land of their birth, but in the main socially excluded, unemployed and lacking the financial means to establish new lives - in Maputo are enamoured with. It could also be that they have fallen in love with what Leipzig represents for them: a weekly reminder of a simpler, happier time gone by.