Aestivalis Akatsuki:
Complete Extra Mission 3.

Aestivalis C (Hikaru):
Unlock 15 secrets.

Aestivalis C (Izumi):
Complete campaign mode.

Aestivalis C (Ryoko):
Unlock 20 secrets.

Alstromeria:
Comlpete Extra Mission 2. Alternately, earn the "30 Ace" rank.

Auge:
Unlock 60 secrets.

Bilbine Camouflage version:
Upgrade Bilbine's special stat until it is unlocked.

Black Selena:
Complete campaign mode.

Daljian:
Unlock 25 secrets.

Gilgazamune:
Unlock 35 secrets.

GP02:
Complete Extra Mission 2.

Johnathan Baronz:
Unlock 60 secrets. Alternately, complete Extra Mission 1.

Layzner MkII Cocept version:
Upgrade Layzner MkII's special stat until it is unlocked.

Nanajin:
Unlocked in Free mode.

Nelly Brain:
Upgrade Yuu Brain's special stat until it is unlocked.

Neue Ziel:
Earn "All Ace" rank. Alternately, deploy 75 units/mechs under any difficulty and mission in Free Mission or Campaign mode.

Oukaou:
Complete campaign mode.

Quincy Baronz:
Unlock 50 secrets.

Yatenkou:
Earn the "60 Ace" rank.

Zakarl:
Unlock 40 secrets.

Zwarth:
Unlock 30 secrets.