The 23-year-old is still awaiting a work permit, but is expected to leave Borussia Dortmund for Manchester United in a £17million deal this summer.
“I want to play (in the hole),” Kagawa told the Kyodo news agency.
“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.
“They’re one of the biggest clubs in the world, and I was given a chance to play for them.
“I took a lot of things into consideration, like the fact that they’ve got a deep squad, their style of football and it wasn’t an easy decision. But I wanted the challenge.”
He added: “There was some talking going on with other clubs, but Manchester [United] were the first to make me a formal offer and the more I talked to them, the more I felt Manchester was the place for me to be.
“I met (Ferguson) and contacted him a few times afterwards. I thought we hit it off, which meant a lot to me. He told me, ‘Don’t worry about a thing, trust me. I would love it if you could take on this huge challenge’.
“And when a legendary man like him says that to you, it carries a lot of weight.”