Sarissa of the Noctilucent Clouds

A mysterious giant creature flies in the upper stratosphere. Where it comes from and what it wants are unknown. Shinobi is a young girl chosen to board a military plane chartered to destroy this 'thing'. But Shinobi is not just another girl. Like a few rare children in the world, she possesses a unique power that allows her to make herself invisible. Only her mysterious teammate can see her when she uses her power...