Kagawa moved to Old Trafford last summer and, though he spoke no English at first, it wasn't hard for him to appreciate just why the Reds manager is so revered in the game.
"He has a magnetic power," Kagawa told ManUtd.jp. "I felt it the first time I met him, from the way he conducts himself and also from working with him on the pitch.
"He communicates well with his players and respects them. As the season went on, I got to communicate with him more, both on football and other subjects. That was important.
"He is a friendly person and his spirit is much younger than his age. I think that's because of his achievements over the years, and also his personality.
"I wish I could have played much longer under him. What he has achieved for the club is tremendous - he is in a class of his own."