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Released originally around , Volume 6 is a key entry in the series for those tracking the progression of specific "junior idols."

The "619" in your query likely refers to a specific file name or cataloging number used in digital archives where these videos are shared, rather than a volume number, as the series typically has much lower volume counts.

The series, often catalogued under codes like SCDV-280xx , is a collection of instructional and performance-based media.