Does anyone know this song?

There's this song, and I think it's either by Gackt or Dir En Grey. I don't remember the name of it, but it's been on my Windows Media Player for a long time now. It kind of starts off really slow and with a piano. The singers voice sounds like it's muffled, and (if you couldn't guess by the band names) it's in Japanese. Erg, I don't really know what they're saying, but the song itself is around 7 minutes long. At around the middle, it kind of stops and then starts again, except its more upbeat when it starts up again. Sorry for the vague description, but do you think you could try to help me figure out what this song is called?