Japan will not fear Germany in their World Cup opener on Wednesday despite Asian teams enduring a torrid tournament so far, striker Takuma Asano says.

Hosts Qatar lost 2-0 to Ecuador in Sunday's opening game and were outplayed, while Iran were on the wrong end of a 6-2 thumping by England the next day.

Lightning-quick forward Asano is convinced Japan will not suffer the same fate when they take on the Germans in Group E and said the Blue Samurai have "nothing to fear".

"For sure there is a difference in the level of Asian teams compared to Europe and South America, and we're still not there yet," said the Bochum striker.

"But you never know what's going to happen at a tournament like this.

"You need lots of qualities like technique and tactics but the senior players keep telling me that the thing you need when it counts is to be the team that really wants it."

Japan have eight players at Bundesliga clubs in their squad and insist they will have no inferiority complex when they take to the pitch in Doha.

Defender Takehiro Tomiyasu, who plays in the Premier League with Arsenal, said Japan will need to be pragmatic but admitted their priority is not to concede goals.

"I don't think we need to give them too much respect," said Tomiyasu.

"Of course we have to be realistic at times. I think we will need to adjust the balance depending on what happens in the match."

Japan have also been drawn with Costa Rica and Spain in a tough Group E.

The four-times Asian champions have never gone further than the second roud of a World Cup but forward Takumi Minamino is not daunted by the quality of the opposition in Qatar.

"Most of Japan's players play overseas and we're competing with players from around the world," said the former Liverpool man, who is now at Monaco.

"With Japan, our opponents might be ranked higher than us, but that just gives us an underdog mindset and that's how we're approaching it."