This Vocaloid song is called: Wisteria Secret.
It is a very ghostly and creepy song that hits the viewer's psyche. If you want to see it, consider it first. I will put the youtube link right above the name of the song. The song is a narration of a murderer and a young girl who was murdered a long time ago.Listen, watch and leave me your comments on how you feel.
By the way, I want to ask everyone how to share the youtube video link here, I'm new to the forum and there are some things I still don't know. Thanks guys so much.
And the important thing I have to repeat again is to be mentally ready before watching.