Review of Koi Kaze
No, absolute trash being glorified as a deep anime. Whether you're someone that detests a brother and sister mating, or advocate towards it, the choice is in your own personal opinion. And if the moral judgement is on you, then you are the one that has to weigh in the pros and cons about that. Concerning the incest topic: Thankfully, we live in a world where laws can regulate moral concerns where traditional common sense fails. More importantly, we are not raw acting animals, despite how we share the same Earth, we as human beings are smart enough to know it's not right to stick your wee-weein everything that fits just because we say we "love" it. Humans have standards, and those standards normally involve basic logic like -don't do it with your own daughter/son, -dont do it with your own mother/father, --don't do it with your brother/ sister, --don't do it with your mom's brother's daughter. These are just the natural common sense bases before we talk about "how young is too young" or "how many is too many." Yet, if you were to ask a nihilist about love, they would just say "everything is possible therefore everything is do-able." Which, in that radical openness, a sane person would argue "just because you CAN do something, doesn't mean you SHOULD.
Concerning the anime's own story:
The anime itself tried to showcase all the red flags about what would happen, and yet, the main characters rejected all their logical intuition and sane reasons, in order to pursue their raw carnal desires. Some might say, "this is true love" because they chose emotion rather than anything else. So some could say "look, raw emotion triumphed." However, "true love" is not just your emotional desires, but also your rational desires. Free will itself is lawless and unbound, yet humans understand concepts like murder, love, and joy far more than just "what they feel like" but "how they should be experienced" like murder in the case of extreme self defense or love in moral virtue, or joy in humility and not in pure narcissism.
This is the core philosophical questions to examine when concluding whether this anime succeeded in this moral topic for the sake of being a romance show. So rather than arguing, is incest a good anime ending, let's just remember there are people in this world that will always say burnt food, with salt, and a dr. pepper make for a healthy breakfast.
Its part opinion, part societal relativity, part philosophical acceptance or defiance to the human rational, not the objective natural freedom.
The brother and sister trope in anime is generally directed in harmless light. But, when we talk about true sister x brother banging, or mother x son, or father x daughter, then that's where the eyebrows get raised.
I for one won't just follow in "oh it's so romantic 10/10." This anime had average production, red flags being ignored in its plot, and ultimately it went full "just follow your heart bro" to the point that it's bad enough she's underage, but she's also your sister. Like c'mon, love has to have meaning otherwise love becomes meaningless.