Because it looks fun (simple mindless hack 'n slay) I gave it a spin.
It's very playable without being able to read Japanese, and it's fun. Simple mindless hack'n slay as I expected, I missed something like this on the DS.
So, 2 things:
The ingame menu basically explains itself, and you can change the tabs with L/R. Double tap (potions) or pull items to slots (weapon, armor) to use. Every level you get to spend skillpoints.
This took me a few minutes to figure out: the skills. You start having 1 skill (blue icon) and have to pull it to a button slot. Use that skill (press the assigned button) close to an enemy and you'll get a bar that fills up steadily. Push your button as fast as you can to 1) kill the enemy 2) regain hp and 3) get skills from the enemy.
Oh and don't die at the first boss -- you'll have to start over