The young Japanese side will come into the Olympics on home turf with high expectations and will hope to start with a convincing victory over their African counterparts.
As the host nation of the Summer Olympics, Japan did not have to go through qualifying to reach this stage, but they still come in as one of the most heavily fancied nations.
They head into the tournament in a strong run of form, having won two and drawn one of their last three games.
That started with a convincing 4-0 win over a senior Jamaican side in a hybrid friendly, with the young team showing their class in a dominant victory.
Hajime Moriyasu's side then built confidence earlier in July with a 3-1 win over a Honduras Under-23s side that they could meet in the knockout stage of the Olympic Games tournament.
Most recently, the Japanese Olympic squad took on pre-tournament favourites Spain in a friendly in preparation for the Olympic Games, and they came away with a creditable 1-1 draw, as Carlos Soler equalised late for their opponents after Ritsu Doan had put Japan Under-23s ahead on the stroke of half time.
They will now look to start the Olympics campaign in a positive manner on home turf, as they take on South Africa's young side.
South Africa qualified for the upcoming Olympic Games Men's Football tournament through the Africa Under-23s Cup of Nations in 2019.
The Amaglug-glug recorded a win over Ivory Coast in the group stage alongside draws with Zambia and Nigeria to finish second and book their spot in the final four as a result.
South Africa would go on to win the third-place playoff in a penalty shootout after a 2-2 draw with Ghana, as a converted Lyle Foster spot kick and a missed opportunity from Emmanuel Cudjoe made the difference in sudden death.
Regardless of their defeat in the semi-finals, the advancement out of the group stage earned South Africa one of the continent's four available spots for the upcoming Olympic Games tournament, and they will hope to defy the odds and pick up a positive result against one of the strongest sides in the first game.
Their only match of the calendar year so far saw David Notoane's side again fall to a 3-0 defeat at the hands of Egypt Under-23s, this time in friendly action, and they will hope to put that behind them as they head into this summer's tournament.
Japan Under-23s' vast array of talent includes Manchester City defender Ko Itakura, who recently spent a two-year loan deal in the Eredivisie with Groningen, and talented Bologna centre-back Takehiro Tomiyasu, who has already featured 23 times for the Japanese senior team.
Their defensive ranks have been further boosted by the selection of experienced centre-back Maya Yoshida as one of the three permitted over-age players, with the former Southampton man having made 107 appearances for the senior national team.
South Africa opted to name only one over-age player in their 22-man squad, with SuperSport United goalkeeper Ronwen Williams coming in for the tournament.
Exciting 21-year-old forward Evidence Makgopa could play a key role in the front line, having netted a brace in his senior international debut in a 3-2 win over Uganda.
Winger Luther Singh also boasts plenty of experience in senior football, having had a productive loan spell at Portuguese top-flight outfit Pacos de Ferreira from Braga last season, registering five goals and five assists in 29 league appearances.
Japan Under-23s possible starting lineup:
Osako; Sakai, Yoshida, Tomiyasu, Tanaka; Doan, Kubo, Mitoma; Ueda, Maeda, Hayashi
South Africa Under-23s possible starting lineup:
Williams; Malepe, Mohamme, Mukumela, Fleurs; Mokoena, Mahlatsi, Dlala; Singh, Makgopa, Foster
We say: Japan Under-23s 2-0 South Africa Under-23s
The Japanese Olympic squad contains an abundance of quality, and with home advantage, they look set to go far in the tournament.
We see them getting off to a strong start on Thursday with a win to please the home fans, as they could certainly outclass South Africa if they manage to click going into the opening game.