Board Thread:General Discussion/@comment-6192846-20140918010005/@comment-6192846-20150106200626

首 also means head, brain, mind, etc. A nozarashi refers to a "skull" and you see it used in the same way we use skulls for clothing, tatoos, etc. Essentially, it makes the first portion mean "the skull head" or simply "skull" for a less literal translation.

Onigashima literally means "demon/ogre island" and like Ninja said, is used in several instances of Japanese folklore. Based on that, it sounds like it means "The Skull at Demon Island" or something to that effect.

If we assume this refers distinctly to a Jakoku-related place/song, then I suggest we keep the demon island's name as "Onigashima" and have the title be "The Skull at Onigashima".

Assuming it does relate to Enbizaka, it could be about the Gackpo character from Heavenly Yard, or one of his ancestors/descendants. As Fifth Pierrot demonstrates, the song doesn't have to have any direct connection to the correlating sin song.