http://www.dlsite.com/ecchi-eng/work/=/product_id/RE149951.html
A new demo has just been released earlier today, from the creator of these other two games:
dlsite.com/maniax/work/=/product_id/RJ121435.html (Horny World of Kunoichi)
dlsite.com/maniax/work/=/product_id/RJ133264.html (Angel Hunt)...