During a space journey, the Risono couple discovered the existence of the evil organization Igarr. To prepare for an impending invasion of Earth, they developed powered suits and created the Giant Squadron Force Man to operate them. Now that Igarr has arrived on Earth and begun its assault, the Force Men continue their battle to protect peace. Among them, Kazuna, the eldest daughter of the Risono family, fights as Force Pink. One day, during a battle against the powerful enemy Torakameleonga, the foe vanishes and fires a tiger arrow directly at Force Pink. Just as the arrow hurtles toward Kazuna, her younger sister, Force Yellow, Sora, leaps into the path and takes the hit, plummeting down to the floor below. To remove the special arrow embedded in her body, they must extract information from Torakameleonga's mouth. Determined to save Sora, Kazuna entrusts her sibling's safety to others and heads alone to the enemy's hideout. With the arrow moving closer to Sora's heart, time is running out. Kazuna swears to Torakameleonga that she will do anything to save her sister. Though Kazuna and Sora are not blood-related, their bond surpasses that of true siblings. Thanks to Kazuna's plan, Sora escapes danger—but the enemy thought defeated, Ebikageru, suddenly grows giant. Sora, possessing mysterious powers, transfers her strength to Kazuna, triggering her transformation into giant-sized Force Pink. Can she protect her beloved sibling and preserve Earth's peace? [HAPPY END]