The game released after Seiren Harp - titled Hi to Tetsu Buresu - you can found dicussions & walkthrough at Hongfire or else. I think NTR-ishes must try once 'cuz it's so good. You roaming around and get groped all the time with dirty guys, you could sell your panty, be prostitutor, whore around topless and do everything you want her to do.
The next game is still in development, here the homepage:
http://scgarden.x.fc2.com/project03.html
(Some pics were modified a little, but i think there's no problem at all)