Other 

●   Do I have to tip a driver?

      No, tips are not necessary in Japan.

●   Where can I meet a driver during my stay in hotel?

      Please stay around the lobby. Bell captain or front desk will call on you

●   For example, if we make a reservation of 6 hour use,

     but actually we use only 3 hours, is the 6 hours use charged?

      Yes. 6 hours of use is charged.