Dmitry Popov has posted an awesome series of manga styled concept art on his Behance profile. The series has been very well received and has recently been listed on the "featured" page (deservedly). I tend to go through phases with manga art. Sometimes I love it and sometimes not so much. I've always preferred the more gritty stuff, and this is a great example. I think the style is very suited to depicting future environments and works extremely well here. Dmitry has amazing talent and is obviously a master of this art. I look forward to seeing more. Check out the Behance link above or his deviantArt page.