About the membership fee courses

• Q.
  What is the difference between the "Monthly Fee Course" and the "Yearly Fee Course"?
• Q.
  How can I change from the "Monthly Membership Course" to the "Annual Membership Course"?
• Q.
  [In-app purchase] Changing from monthly to annual membership
• Q.
  Can I change from the "Annual Membership Course" to the "Monthly Membership Course"?
• Q.
  Can I register for both the "Monthly Membership Course" and the "Annual Membership Course"?
• Q.
  Can you check if the course has been changed?