So, the entire series could be considered as highly successful.

The series is up to number 4, and is considered a hit in Japan.

Since most of the volumes are priced at $49.99 or higher, the series can be considered expensive.

The series is generally considered among the best "easy readers" for young children.

Because of this, the series is now considered to be out-of-print.

The series is considered to be one of the most popular of the 1990s.

The series is generally considered to examine two broad themes.

The series is usually considered in three groups which broadly mirror the order of their creation.

The series can be loosely considered a magical girl story.

The first series is considered to consist of 21 episodes.