Katsuragi Marina meets a familiar named Aramaki by accident and transform into Magical Girl Pastel Marie☆彡! As Magical Girl, she has to close Dimension Hole that occasionally occur. The Dimension Hole release miasma that turns people into monsters! Will Marina defeat all the monsters and close the Dimension Hole safely? The battle that must kept secret to the world begins! This independent work developed from the "Heroine become Magical Girl" scene in the original Kouyoku Senki ExS-Tia 3 work. Instead of the SF transformation from the original ExS-Tia works, this work give the heroine doing her activity with frilly uniform, enjoy as you watch her erotic scene when defeated.