Koi Kaze, Hourou Musuko Recommendations
Both of the series have an understated, muted art style, although Hourou Musuko animation is superior. (This is unsurprising considering Koi Kaze was released in 2004.)
The real similarity doesn't lie in the similar art style though. No, instead both series grapple with difficult societal concepts in a mature way without resorting to tasteless humour of it, although the incest in Koi Kaze is 'more taboo' than the gender difficulties in Hourou Musuko.
If you like one, you'll likely like the other.
Transexuality and incest; two topics that, whenever used in anime, tend to be "humoristically" depicted. In Koi Kaze and Wandering Son, however, the subjects are explored in incredibly serious and mature manners, turning both shows into must-sees for those who've grown tired of the kind of shows previously mentioned.
Another good drama with a delicate topic, Hourou Musuko deals with gender identity. Similar to Koi Kaze in the sense that it takes a serious approach where other anime use comedy. Different topics but a more similar genre, I think it fits the mood more than other generic incest anime.
Both series adopt a very mature mentality when dealing with socially taboo topics and situations, remarkably conveying the hardships and challenges that the characters in each face as expectations and social norms step in to confront the concepts in a vivid and disturbingly real manner. They are both very character driven stories and carry a degree of emotional impact that is not forced but softly portrayed and carefully presented.
Both handle complicated social concepts is a very mature manner. They tell a concrete story, but leave the verdict of whether the actions characters take are ultimately right or wrong up to the viewer.
Outside of the expressive minimalist art style the two share, what struck me the most about both of these is the use of silence in sound design. Both of these shows have a lot of scenes in which there's sparse music and dialogue, creating this personal, uncomfortable, and awkward feeling that greatly works to the shows' advantage.
Both shows delve into some aspects of taboo or down right forbidden culture. Hourou musuko is much more light-hearted admittedly but there is still tense drama and emotion wrought throughout the scenes. Character motivations are incredibly unique and difficult to understand but thats what make's these show a must watch!