The junior, Mai, who thinks of Nanoha. And then, the school trip… "Good things often attract trouble," a saying that means good things are often interrupted, like "clouds gathering around the moon and storms around flowers"── The one who discovered the secret relationship between Nanoha and Chidori is the junior, Mai. She is Nanoha's childhood friend and has harbored a faint love for her all along. What will Mai's presence bring to the two of them...? In the midst of this, Chidori and the second-year students are off to Nagasaki for their school trip…!!