kuroku

Hi, I'm hoping someone could help me with this issue. ; I'm having trouble finding this one particular manga about a guy with his girlfriend. They both go on some field trip, (I think) and at some relic or some part of a museum (I seriously can't remember the location very well) the girlfriend recovers her memories and realizes she's the reincarnation of Ishtar or something and then goes into the past.

The boyfriend, being left behind gets desperate, wants his girlfriend back sees Enkidu as a ghost, and makes an agreement with Enkidu to let him host his body and he goes into the past to Egypt... Or Mesopotamia, I forgot. It's been a while since I read it, so I hope I got it right. OTL

I do remember for sure that the girlfriend has black hair, long and straight.

So I guess it's categorized as historical, but I'm seriously having a hard time finding the right title. I tried google, but of course it keeps giving me yugioh or the epic of gilgamesh or red river. Awesome, but I wasn't looking for that, lol.

I don't really know if it's shojo or shonen either. orz

Does anyone know the manga I'm talking about? ;