Kouhei Hayami (also known as the Libra Zodiarts) is the principal of Amanogawa High School and a major antagonist in Kamen Rider Fourze. He is secretly one of the Horoscopes and is working to find users for all twelve Horoscope Switches to initiate the Day of Awakening.
He was portrayed by Kousei Amano.
Hayami transformed into the Libra Zodiarts to bring back the unconscious Sarina Sonoda after she was defeated by Kamen Rider Fourze, casting an illusion to protect her identity. Hayami then took over her duty of handing out the Zodiarts Switches. After the Dragon Zodiarts was defeated and Sonoda was banished to the Dark Nebula by the Virgo Zodiarts for failures, Gamou tells Hayami to speed up his recruitment.
When Natsuji Kijima became the Cancer Zodiarts and joined the Horoscopes' ranks, Hayami took a dislike to the newcomer for his disrespect towards him. After Kijima was defeated by Kamen Rider Meteor, Hayami takes the Cancer Switch that Kijima accidentally dropped and projected the illusion that Kijima was actually a detective investigating them to get Virgo to banish Kijima.
Gamou later sends Hayami to Kyoto to destroy the four altars of Cosmic Energy that are sustaining The Hole over Kyoto so that AGHS becomes the only place to have a vortex where Cosmic Energy flows into. Needing Fourze to be present to complete the plan, Gamou has the field trip is changed to Kyoto and also sends Kou Tasugami, the holder of the Leo Switch, to supervise Hayami's progress. After three altars are destroyed and the Leo Zodiarts defeated Meteor, Libra faces Fourze.
After Fourze's Cosmic States Rider Super Galaxy finish flung Libra into space, Virgo transported him back to the Horoscopes' lair as Libra destroyed the last altar. Despite this, Gamou tells Hayami that he is no longer of use to them and orders Virgo to banish him to the Dark Nebula. However, Libra's desperation to not be sent to the Dark Nebula causes his Supernova powers to manifest the Eye of Laplace, causing Gamou to stay off banishing him.
Hayami later began to question Gamou about the Horoscopes' goal, asking if Gamou wants him or his Horoscopes Switch. After learning about the Day of Awakening, Hayami attempts to find someone to become the Pisces Zodiarts, the final Horoscopes member. Hayami eventually identifies Ran Kuroki as Pisces and comes up with a scheme to get her to use the Switch. Hayami pretends to have defected from the Horoscopes to protect Ran, giving the Kamen Rider Club his Libra Switch and information about the Horoscopes as a proof of his betrayal. However, after Ran becomes the Pisces Zodiarts to protect him, Hayami reveals he was only faking his betrayal and reobtains his Libra Switch thanks to Tasugami. When Fourze attempts to stop Sagittarius from causing the Day of Awakening with a Rider Super Galaxy Finish, Libra takes the blow and is sent into the Dark Nebula, where he is vaporized by lightning from the vortex and killed.