Nanoha and Chidori are best friends who attend the same all-girls high school--and also share a heart-pounding secret: they're lovers. Through sunny days and tumultuous storms, they're always ready for new adventures together.

Mai, an underclassman with a crush on Nanoha, finds out about Nanoha and Chidori's secret. Her very presence sows discord between the usually inseparable couple. Can Nanoha and Chidori overcome these communication issues without letting frustration get the best of them?