Koi Kaze is about Koshiro and Nanoka who are brother and sister separated since Nanoka was a baby. When the time comes for her to enter high school, it is decided that the two will live together. Although off to a shaky start, they are getting used to living under the same roof. Koshiro begins to realize his feelings for Nanoka, even after trying to ignore them.
This causes him a great deal of distress. Even though he treated her harshly, Nanoka can't stop thinking about how much she likes him. They know what they feel is wrong, but their feelings for each other are moving them closer together. MMOKnight Though they know what they are doing is wrong, they can't control their feelings for one another any longer?