Secret missions hint:
Earn an “A” rank on all missions without letting any missions expire to unlock secret missions. Note: Every character has a secret mission and are unlocked at the same time.
Mission order: None expire:
Play the missions in the following order so that none of them will expire: Louise 4, Kia 6, Kia 2, Kia 3, Kia 5, Louise 5, Kia 1, Louise 6, Kia 4, Louise 1, Louise 3, and Louise 2.