I was looking for Volume 3 of the manga and came across this facebook group which has the raws for volume 3. I request sorel21 to look through it and check if it is indeed the right volume and start working on the translation if possible. It will be really great if the 3rd volume is translated. Links are provided below.
1) https://es-es.facebook.com/media/set/?set=a.368527506494654.108782.190831950930878&type=1
2) https://www.facebook.com/media/set/?set=a.368534846493920.108785.190831950930878&type=1&comment_id=92836322&offset=0&total_comments=1
3) https://es-es.facebook.com/media/set/?set=a.368541953159876.108788.190831950930878&type=3
4) https://es-es.facebook.com/media/set/?set=a.368548603159211.108789.190831950930878&type=3
5) https://es-es.facebook.com/media/set/?set=a.368551286492276.108791.190831950930878&type=3
Well I found raws of chapters 1-5 of volume 3 if that helps, I'll see if I can do more digging :) Here is the link:
http://www.mediafire.com/download/uvzmhlmbjqy/Aijin_Incubus_v03-c1-5+%28jp+raw%29.zip
I'll translate the rest of this from Japanese to English if someone can link me to the RAWs for volume 3 and 4, etc