Looking for an Old Hentai?

So I'm trying to remember this old Hentai-ish anime from years ago. I think it was in made in the 90s and I use to own it on VHS. I remember it had a mecha in it, I think it was powered by women's orgasms or something like that. I remember that there was a battle in the mech from the forest and that one of the girls was in a bath that she was piloting. I honestly could be mixing up another one on my old shelf. I also have a copy of an old picture of the VHS tape but it is so blurry that I have no clue what it is.

http://img.photobucket.com/albums/v440/se37/Untitled-1_zps4kkk5hio.jpg

I know what everything else on the shelf is and the one in question is the red box between Neon Genesis and End of Summer VHS tapes. I am hoping someone will know what this one is.