I bought this version on Dlsite, there is one more set of illustrations than the old version.
The two girls with long hair are the same sisters from the first one of this serie: https://e-hentai.org/g/1404234/a5eb00e817/

You can support the artist here:
https://www.patreon.com/kokkeinagaya
https://katote22fan.fanbox.cc/
https://fantia.jp/fanclubs/1861
https://www.pixiv.net/en/users/3611234