https://www.suruga-ya.jp/product/detail/ZHOI15701

This appears to be the omnibus of all three HARMONIOUS releases, the first of which was initially released on CD before being published in this book.
HARMONIOUS: https://www.doujinshi.org/book/66467/HARMONIOUS/
HARMONIOUS 2: https://www.doujinshi.org/book/57866/HARMONIOUS-2/
HARMONIOUS 3: https://www.doujinshi.org/book/12067/HARMONIOUS-3/

Some of this material can be seen in these earlier releases:
HARMONIOUS (digital): https://e-hentai.org/g/34716/398a994fbe/
HARMONIOUS 2: https://e-hentai.org/g/253418/6db6980c94/
HARMONIOUS 3: https://e-hentai.org/g/253419/43df834ae0/

This release has additional pages, is of much higher resolution, and has better color. However the two-page spreads have been scanned and cropped in a way that arguably makes the previous releases superior for those pages.

thanks for sharing

Base +6, Arndress +2