The Internet, where anyone can easily come and go. In this virtual cyber world, a magical being with a will lives.... A strange rumor whispered among net surfers. It was a rumor that if one accessed the address "siren", he/she could experience virtual sex with a beautiful girl living in the Internet. In reality, however, those who access the address invariably disappear mysteriously. Ohtaka, who works for a computer software production company, heard this story from a colleague and at first thought it was ridiculous. One day, however, he goes missing, leaving behind a note with the address of "siren".