Shout! Studios distributes in the US.
Directed by Svyatoslav Podgaevskiy (Queen of Spades: The Dark Rite, The Bride).
This is a Russian horror film that's reportedly based on Russian legend that girls who drown turn into mermaids, staying in the rivers and lakes forever. At night, they seduce men with their singing, and lure them to the bottom of the lake, where they become guards, protecting the mermaids.