After a difficult buildup to the tournament, Akira Nishino's team showed their true capabilities when they stunned Colombia 2-1 in their opener on June 19.
While there is no denying Colombia played almost the entire match with 10 men after Carlos Sanchez was sent off, Japan showed grit and determination in pulling off the win after the South Americans had equalised through Juan Quintero.
Shinji Kagawa had given the Samurai Blue the lead off a penalty awarded when Sanchez handled the ball in the third minute while Yuya Osako scored the winner in the 73rd minute.
It was a result which Nishino had dreamed of and Japan take on Senegal knowing that a win should take them through to the Round of 16 for just the third time.
Japan, however, know that they can't take Senegal for granted as the African side were equally impressive in their 2-1 win over Poland.
"It's going to be tough, they have great players. They're physical, they're fast and they'll play in front of a big crowd," said Japan's attacking midfielder Keisuke Honda.
Still, Japan should be on a high as the win over Colombia was historic - it was the first achieved by an Asian side over South American opposition at the FIFA World Cup - and the troubles Nishino's men faced in the buildup should be a source of further motivation for the four-time AFC Asian Cup winners.
Senegal, though, will be equally confident of their chances after their superb display against Poland.
Powered by English Premier League side Liverpool's Sadio Mane and M'baye Niang of Italian club Torino, Japan will have to contain Senegal's speedy play.
Poland struggled to contain them and Japan will have to be at their defensive best to stop Senegal from inflicting damage.
Did you know?
This will be the fourth time Japan will be facing a team from Africa in the FIFA World Cup - they defeated Tunisia 2-0 in 2002 and Cameroon 1-0 in 2010. The Samurai Blue, however, lost 2-1 to Ivory Coast in the 2014 edition.
Photos: FIFA via Getty Images
