What do you think of japanese enterprise?

My new boss used to work in a Japan enterprise and it lasted more than 10 years. He is not happy when he sees you off duty on time, but very consent in working overtime.
And i asked my friends who work in the Japanese enterprises, they are confessed that most of the time they have to work overtime.
What do you think of the working-overtime ? Is it good or bad ? Do you like to work in such enterprises, why ?