Currently available on 2 streaming services.

Dark Gathering - watch online: streaming, buy or rent

Currently you are able to watch "Dark Gathering" streaming on Netflix, Catchplay.

Cast

Yu Sasahara
Yayoi Hozuki (voice)
Nobunaga Shimazaki
Keitaro Gentoga (voice)
Kana Hanazawa
Eiko Hozuki (voice)