* 1 BVC lesson=40 min class + 5 min break
* Minimum unit of 1 lesson: 2 lessons
* For Group BVC lessons, 60 minutes per lesson × Twice a week on a fixed schedule
* Course period (+grace period):
- Private 1 time: 1 month
- Private 10 times: 2 months
- Private 25 times: 4 months
- Group 16 times: 2 months
