Cloud- Can be bought at Battle Square for 32000BP

Barret- Can be found later in the game in a tent of North Corel

Tifa- Play the Highwind Theme TWICE on her piano. The buttons you press are:

X, Square, Triangle, R1+Triangle, R1+Square, X, Square, Triangle, R1+X, Circle, X, Square, X

RED XIII- Inside the safe in the mansion of Nibleheim.

Cid- Get it from Treasure Chest on Sunken Plain

Vincent- During the 2nd CD, you must go to the lake with a waterfall and talk to the lady. Visit again on the 3rd CD, she will give you Vincent's manual.

Yuffie: You must go to the back to her hometown and fight 5 members of Yuffie's family.

Aerith:There is a sleeping man southeast of Midigar, in a cave. He tells you how many battles you've fought - if the number is over 600 and the last two digits are the same, he will give you Mithril. If you take this to the Blacksmith (the one who you visited before going to the Setora Shrine), he will give you the option to open one of two chests - the smaller contains Aerith's manual.