From what I have seen, the animation looks very good. The character design is very interesting and so is the plot.
Humans have devastated the Earth, destroying what little remained of nature. Many species of animal are either extinct or on the brink of extinction. There is a legend of wolves appearing just before the end of the world to lead everyone to Paradise. No one believes these legends, however, because they believe wolves have become extinct over 200 years ago.
However, wolves do still live and thrive, and only are able to do so by developing a special ability to manipulate people's minds so that they see the wolves as humans. In this way, the wolves can co-exist with humans with the humans being none the wiser. Many wolves integrated themselves into human society, becoming common workers, gang members, and even lowly street dogs. Many who had once desired to seek paradise had lost interest in doing so, settling instead to live among the humans.
The four wolves, Kiba, Tsume, Hige and Toboe, all have their own individual goals, but all desire true freedom, away from the humans. They are searching for the mythical Paradise, but in order to do so, must find the Flower Maiden. However, they have much opposition, in the form of Quent Yaiden, the hunter who wishes to eliminate all wolves from the face of the Earth, and his dog Blue, who helps him locate the wolves. There are also the detective Hubb Lebowsi, and the various research scientists, including Cher Degre, who wish to prove the existence of these wolves. Yet another obstacle is the mysterious Darcia, who kidnaps Cheza, the Flower Maiden who can sense the wolves' emotions and pain.
Kei Kusanagi is a shy high school student with a troubled past due to a strange condition he has that causes him to "withdraw" in times of high emotional stress. One night, he witnesses the appearance of an alien. The next day, his class gets a new teacher, who turns out to be the alien woman he saw the night before. When the two accidentally get caught in a compromising situation, they pretend that they are married (with reasons given as to why such a marriage would be legitimate) and thus must begin to live their lives together as a married couple.
This anime is similar to the Ah! Megami-sama plot. Beautiful woman came out of thin air and meets a lonely boy, who begins to like her. ^_^' But I have heard it gets more involved than that. I actually haven't seen more that the first episode but I will get around to it.