What are all the ways I can gain SP?

In the Final Fantasy VII Remake, there is a new mechanic to upgrade and improve your weapons. In order to do this, you need to use SP.

So far, the only way I have found to gain SP is to level up your characters; which is about 5 SP per level. My characters are getting into higher levels, so progression in gaining SP this way is starting to become slower (especially for the upgrades that take more than 5 SP).

Aside from leveling up, what are all the ways I can obtain SP to upgrade my weapons?

Solution 1:

There are a number of books you can obtain which give 10 SP. Each type of book applies to each character.

• Cloud: The Art of Swordplay
• Barret: Sharpshooter’s Companion
• Tifa: Way of the Fist
• Aerith: Telluric Scriptures

Some you can buy with Moogle Medals in the Sector 6 Slums, some from side quests and others must be earnt in the Corneo Colluseum.

There are 14 volumes for each character, and volumes after 3 must be earnt in hard mode.

I've been a bit brief to avoid spoilers, but the full reference is here if you need: https://www.rpgsite.net/feature/9637-final-fantasy-vii-remake-manuscript-list-where-to-find-all-skill-books-and-manuscript-volumes-for-weapon-upgrades