Setsuno Muda is a high school boy with a cruel fate, trapped in a forbidden love for his blood sister and inhabited by the spirit of the Organic Angel Alexiel. As the final battle between Heaven and Hell approaches, and forces gather against him, he must soon make decisions that will inevitably alter his future for better or worse. But for poor young Setsuno, his anguish and torment might be more overwhelming than the blood on his hands, as conflicts are settled and lives are changed forever...
If life teaches us anything, it is that love sometimes happens in the most unlikely of places, with the most unlikely of people. Koshiro is a run-of-the-mill salaryman who has recently been dumped by his partner. With his heart broken and hope lost, he soon comes to realize that he can love again, once he sets eyes on a beautiful young schoolgirl riding the train. However, there is one catch -- this girl named Nanoka is his sister, who he has not seen in years. Knowing that their forbidden love will always be scrutinized by society; will Koushirou and Nanoka be able to resist the temptation?
The reason for recommending the two series is for the motif of incest. While not having much else in common, you should check out Koi Kaze if you liked the sibling love motif in Angel Sanctuary.
Nagamine is a young high school student who lives a fairly typical teenage life: hanging out with friends, attending class, and falling in love with a wonderful boy. But when she enlists in the galactic army, who is desperate for candidates to fight an alien war, she finds herself drifting farther away from her first love, Noboru. In the depths of space, where a simple email takes eight years to be delivered, will their love truly flourish, or simply fade away?
Although very different, both Voices of a Distant Star and Angel Sanctuary have beautiful animation, a heartbreaking story, and one common theme: tragic, doomed love.
Keiichi Morisato is just your average college student until one day, fate interjects as he makes a call for take-out food. Unknown to him, he reaches the Goddess Help Line, and contacts a goddess named Belldandy, who grants him a wish. Thinking it to be a joke, Keiichi wishes for her to be his girlfriend 'forever'.
Whenever Kippei is at school, he has one thing on his mind: girls. From skipping class to cheesy lines, he'll do anything it takes to reel the ladies in, though he never seems to find the right person. But the bachelor lifestyle is soon to change when young Yuzuyu enters the picture. This five-year-old cutie has been abandoned by her mother, and is to be taken care of by none other than Kippei! Unfortunately for the both of them, Kippei has no experience raising a child, so the learning curve will be quite steep...
If you liked how serious topics were touched in Angel Sanctuary or Ai Baby, forcing the characters to make decisions because of their loved ones and family, then you'd like the other. Angel Sanctuary is way shorter, with only three episodes, but both have a familiar feeling.
Hamura Shou is a young man who has been searching for his long lost younger brother named Kai since childhood. After transferring to an all-boys school, he manages to find him – but Kai denies it, and him in the process. Meanwhile, in the magical world of Winfield, the white-winged beings of the royal family have been killed and exiled, leaving the throne to its enemies. Through a series of events, the link between Earth and Winfield will be revealed – a link which will turn friends against each other, and cause tragedies to occur.
Angelic bishounen involved in a conflict is the basic idea behind both Angel Sanctuary and Angel's Feather. Both are somewhat disjointed due to fact that the original formats of manga (in the case of AS) and game (in the case of case) contained too much information to be fully explored in these OVAs. A dramatic romantic involvement that includes incest (much more obvious in AS but heavily hinted in AF as well) and a supernatural element that relies very heavily on wings/angel-related imagery make these two anime a perfect match.