No in-game methods that I know of, but in case you'd ever like to try your hand at modding you can get the engine itself
here! It should be feasible to increase the stats of each character.
The Big Caveat ™ is that the user interface is in Japanese, but if you hold your phone to the screen with Google Translate, you can find your way around. I'm trying to
translate the engine (to help speed up my Mihashira translation/modding) and will probably drop that here for anyone interested to play around with too, once it's done.
But since that's a lot of effort, if you just want a normal ingame way to recover health/mana easily:
- Hashitaka - spam parry
- Kigis - spam 'whack stuff with stick'
- Ikaru - spam dodge (must iframe through attacks or projectiles)
And that will restore both health and mana for each successful action.