Blue Seed (1994)

S1E16 Japan Is a Paradise! Tears in Wakasa!

Kunikida sets off to look into the mysterious death of his former friend, where he encounters his young wife, who harbors a dangerous secret. At the same time, grotesque corpses start to accumulate, and rumors of the "Thousand Year Nun" emerge—a bizarre figure said to maintain her youth by feasting on the flesh of mermaids.