Wateru, oh that RPG, in a RPG spoof that is not slayers. Well the last time I heard about Wateru was back when we still had things called malls. A man setup a small shop area, selling imported animation, and videogames. Had a sign detailing his venture to Japan. Mentioned the people their kept calling him Wateru ( which he did look like ), he was selling devil lady, and a couple non-hentai stuff.
The next place I heard of him, was in Megaman Legends where you have the option of the junk shop keeper calling you "Wateru" or something else. I think his name also appears as a joke in a couple of other games as well. I think in Mystical Ninja N64.