Osamu Mutoh is a minor character in the manga. He is the manager and supervisor of Salon de Marie.
What is shown in the manga of Osamu is a very cold man, even to people in his same grade like Kurosu Mamoru. He was very silent and strict to Ichigo the first few days, letting her mop the floor and do the dishes, even turning away from the bullying she gets from Chief Yamane. He wouldn't even let her practice in the kitchen after work. However, he does soften up as he sees how Ichigo keeps working hard at the things she can't do, such as wrapping paper and making the custard. He was impressed by Ichigo's will and later even acknoledges her talent along with Kurosu, and her start in the kitchen later on.