You get them all over the world.
I don't know all of them but go on gamefaqs.com
20
You go to Spirit Island (southwestern map in the middle of the triangle rock formation at the bottom of the map), and with ten gems, your sword will upgrade to the spirit of the ten courage gems you gathered.
it's in the courage temple.
In the Temple of Courage.
You Can't
which part
On Molida Island.
it is in a treasure chest
Molaida Island
you cant
you get it in the temple of courage at modlia island