Fumihiro Nitta is a first-year student who is a member of the fencing team who was used by JK as his human shield from bullies.
As a result of injuries from taking the beatings, Nitta was unable to enter a fencing tournament before learning of JK's deception and vowed to take his revenge. The chance for payback on JK presented itself when the Scorpion Zodiarts gives him a Zodiarts Switch that allows him to transform into the Unicorn Zodiarts.
While fighting Kamen Rider Fourze, Nitta's desire for revenge causes a sudden evolution in his Zodiarts form where his horse-faced mask converts into the Longsword Monarch rapier. This new power, combined with his ability to project horseshoe-shaped energy projectiles, makes the Unicorn Zodiarts a force to be reckoned with in a fight. After capturing JK, Nitta amusingly allows him a chance for freedom by contacting someone for help, with full knowledge that no one in JK's circle would save him. However, Gentaro, thought to be the last on the list who'd actually come save JK, proves Nitta wrong by coming to save the guy who betrayed his trust. Gentaro manages to transform into Kamen Rider Fourze Elek States and destroys the Zodiarts with the Rider Ten Billion Volt Break. Though JK intends to beat the daylights out of Nitta for slighting him, Gentaro stops him while reminding him that he is the one in the wrong in the first place, while offering his friendship to Nitta.