Apparently Osorezan is a mountain in Northern Japan with a Buddhist temple and believed in Shintoism to be a gate to the underworld... Happy Honeymoon!
Ooh, a yandere release. With a title like that, it's kind of fitting.
'What did I get myself mixed up in', though? Well...You picked up a suffering girl who was um, trying to curse her parents to death and now you're fully responsible for making her happy.
Good luck, man. Just sign the marriage registration form and you're set...