Also known as: 斎藤治
An unlockable character from Mahjong Soul.
He has short Black Hair. His eyes are grey. In most art of him, he can be seen wearing Glasses.
Osamu is perfect as a company director; he is calm, decisive and performs his daily routines like an accurate robot. When it comes to work, he is strict to himself as well as his employees, so they often refer to him as the "Devil Boss". If one has to find out a weak point of his, it is probably his younger sister who is still in high school, Mami.