Let me start this review by saying that Koi Kaze is the most depressing anime I have seen. A love that cannot blossom does just that gradually throughout the series, with the viewers’ sense of dread building along with the story. This is not for kids.
There are MINOR spoilers when describing the story/characters below. Nothing too major but I thought I would mention it in case the reader wants to go in knowing near to nothing.
The plot of Koi Koze is very simple -- A brother and a sister who haven't seen each other since they were very little start living together (along with their father) when 15 year old Nanoka (who had been living with the siblings’ mother) needs to move closer to her new school. The brother, Koshiro, is 27, meaning there's a 12 year age gap between the siblings. The two instantly have a connection and feelings for each other that go above simple friendship/family feelings.
Before the pair learns they are brother and sister, they bump into each other on a train after Nanoka drops her ID card. They later randomly bump into each again, ending up going together to an amusement park since Koshiro had just been given 2 tickets. They end up having a heart to heart, telling each other about their love problems, Koshiro ending up crying. They find out they are siblings when their dad meets them together as they're exiting the amusement park.
Koshiro's initial reaction to the sister revelation is to be nasty to her, hiding the conflict going on inside himself. He doesn't want to face up to his feelings for her, choosing instead to simply act like a bad brother. Nanako, being young and naive, initially has no idea about Koshiro's feelings and doesn't understand her own, leading her to be confused about Koshiro's transformation from nice guy to bad brother. She does manage to discover he does care for her due to his actions - concerned when she has period cramps, worried when she's out in the rain, jealous when she's talking to boys, etc.
As you might have worked out after reading the above, Koi Kaze deals with a taboo subject without really holding back. That doesn't mean incest is glorified here (if anything it's the opposite since the story is tragic); what the story does is show a true love that can never be in this world. Both parties don't want to feel how they do; they just do and cannot change it.
The series progresses at a slow pace as their relationship develops. At first it bothered me that nothing seemed to be happening, but once it gripped me the episodes seemed to be going much faster. Give it chance before dropping it.
With the focus being on the love between two siblings, the two get a lot of attention.
Koshiro is constantly in conflict with himself throughout the series. His brain knows what he's thinking and doing is wrong, yet his heart tells him otherwise. He tries to hide his inner conflict from Nanako by simply being a bad brother at first, attempting to push her away. His guilt over how he feels eventually drops down and allows him to be VERY friendly with her, but he still knows it's wrong to think and feel how he does about his kid sister.
Nanako, on the other hand, doesn't have the same conflict Koshiro has going on right from the start. Being naive, she takes his aggressive attitude as nothing more than him being a bad brother, not able to understand what reason he could possibly have to act the way he does. She does eventually start to understand that her own feelings are above and beyond sisterly love, leading to the feelings of both coming out in the open.
Both characters have a lot of depth, as you'd expect. The rest of the cast don't really get fleshed out very much, but that doesn't matter an awful lot when the 2 most important characters do get fully fleshed out, hence the high rating.
::Art / Animation::
It looks and moves well enough for a show without any action sequences. The art, while not of the highest level, looks good enough to make Nanako look like the cutest thing I've ever seen.
There are no problems, the series is in wide-screen and it looks more than good enough for a series that doesn't have action driving it onwards.
I didn't like the soundtrack very much at first due to there not being many tracks that stand out. However, on reflection, I understand that the music used was pretty much perfect for this type of show - it's irrelevant how many tracks there are that I'd listen to away from the series; the only thing that matters is that the music fits the series and sets the right mood for whatever scene it's playing during, which the Koi Kaze soundtrack does.
Overall, Koi Kaze is one the best series I've ever watched...along with it being the most depressing and one of the most unsettling. If you can handle a tragic story, this series is unmissable.