Things I wanted in this game;
Yuuka protagonist, warrior, mage, sorceress or witch. I'm already imagining the outfits...
It could have H events during your training and combat with enemies.
Lust factor, increases based on the actions of people and enemies and the choices of the protagonist.
The shards would have another meaning, that if she doesn't recover all the shards she will give in to lust and become a slave to pleasure.
That is, for the true ending Yuuka would have to recover all the fragments avoiding giving in to temptations along the way.