Manchester United recently introduced their first signing of the summer transfer window last week with the arrival of Shiniji Kagawa from Borussia Dortmund to Old Trafford.  Kagawa made the first public statement on Wednesday regarding his move to the English giants.

Kagawa told the Japanese press after returning from a World Cup qualifier in Australia that he was excited about the move to United but also admitted it would be a great challenge .

"No doubt, it will truly be a big challenge for me, and I realize that mistakes will not be tolerated," Kagawa said.

"I have to work harder than ever. I have to take this step with that sort of resolve," Kagawa went on to add.

United sealed the deal for the 23-year old Japanese International on June 5 for £12m from Dortmund. Kagawa becomes the second Asian player after South Korean International Park Ji-Sung. Kagawa becomes the first Japanese player to play for United. In his two seasons in the Bundesliga, Kagawa scored 21 goals in 49 appearances.

Kagawa revealed that Ferguson told him the transfer would be a huge challenge but wanted him to feel he could put his trust in his new manager.

"I was grateful to hear that from such a great person," Kagawa said.

Kagawa is subjected to medical and work permit which seems to be a mere formality. Kagawa had long been linked with Arsenal and AC Milan alongside United.  Kagawa finally chose to join United. Kagawa went on to add "Manchester (United) was the club that I most wanted to go to."

Kagawa has been a key player in Dortmund's success helping them win two domestic cups in two years and also a cup double last season. Kagawa has scored 21 goals in 49 appearances for the German champions.

Kagawa can also play down the left side, but Kagawa is eyeing a more new role for United.

"I want to play (in the hole)," Kagawa told the Kyodo news agency on Wednesday. "I feel like that's where I play my best football. I plan on working hard so I can win my place at the position.

Kagawa cost Dortmund just 350,000 Euros when he joined from J-League side Cerezo Osaka in 2010 and has been a key player in Japan's recent International success. Japan leads the five-team Asian Group B on seven points from three games, followed by Iraq, Australia, Oman and Jordan.

United missed the likes of Eden Hazard who preferred to join the Champions League winning side. Will Kagawa be a star at United and is he the next great No. 7? It stands to be reasoned that Kagawa needs to be given No 7. because of his potential to be a great player for Manchester United in the future.