自过去的五年以来，世界似乎已经恢复了和平，几乎没有任何亚马逊的踪迹。然而，一种被称为"Amazon化"的现象却在不断蔓延，普通人被亚马逊细胞感染，逐渐变成了可怕的亚马逊生物。为了对抗这一威胁，政府成立了一个秘密组织，名为4C，专门负责驱除亚马逊化的人类。

在这个组织中，有一个少年名叫千翼，他在幼年时期被亚马逊所养大。千翼获得了变身成假面骑士Amazon Neo的能力，并与亚马逊们展开了战斗。然而，在他面前出现了一位名叫优的少女，她变身成乌鸦亚马逊，是一个被作为生物兵器的Sigma型亚马逊。尽管千翼曾被自己的亚马逊本能所驱使，但在遇到优之后，他第一次没有产生"想吃"的欲望，反而被她吸引了起来。

优的身世非同寻常，她的真实身份是被亚马逊化的父亲杀死后复活的Sigma型亚马逊。她为了摆脱被亚马逊控制的命运，选择了与千翼并肩作战。他们开始合作，共同对抗邪恶的亚马逊们，并试图揭开背后隐藏的阴谋。

在这个充满挑战和危险的世界中，千翼和优将面临各种艰难的抉择和战斗。他们将不断成长，并逐渐揭示亚马逊背后更深层的秘密。这是一场正义与邪恶的较量，也是一个关于勇气、信念和牺牲的故事。

Since the past five years, the world seems to have returned to peace, with hardly any trace of the Amazon. However, a phenomenon known as "Amazonization" continues to spread, and ordinary people are infected with Amazon cells, gradually turning into terrifying Amazon creatures. To combat this threat, the government formed a secret organization called 4C, tasked with exorcising Amazonized humans.

In this organization, there is a boy named Qianyi, who was Period was raised by Amazon. Chiba gains the ability to transform into Kamen Rider Amazon Neo and fights the Amazons. However, a girl named Yu appeared in front of him, and she transformed into a crow Amazon, a Sigma-type Amazon that was used as a biological weapon. Although Qian Yi was once driven by his own Amazon instinct, after meeting Yu, for the first time, he did not have the desire to "want to eat", but was attracted by her instead.

Your life experience is extraordinary, her real identity is Amazonized A Sigma-type Amazon revived after his father was killed. In order to get rid of the fate of being controlled by Amazon, she chose to fight side by side with Qian Yi. They began to cooperate to fight against the evil Amazons and try to uncover the hidden conspiracy behind them.

In this challenging and dangerous world, Qian Yi and You will face Various difficult choices and battles. They will continue to grow and gradually reveal the deeper secrets behind Amazon. This is a contest between justice and evil, and it is also a story about courage, faith and sacrifice.