Extra Menu
     Beat  the  game  once  and  make a clear save. This will give you
access  to the Extra's menu in the main title screen. Every subsequent
playthrough  extra  endings  are  added  to  the  gallery,  as well as
Encyclopedia information.
     The following information is unlocked once the game is cleared:

     Gallery  -  Picture  Gallery  of  all  the  characters and ending
portraits based on your saved game.

     Database - The Encyclopedia of Monsters, Alchemy Items, and Recipe

     Music - The OST in game

     Cast - Listen to the thanks of the Japanese voice cast

     Endings - View all unlocked endings


Bonus Dungeon
     Beat  the game once and make a clear save. Reload any save before
the last boss and go to the world map.

     In the World Map there is a place called the Old School Building.
A  sub-section  of  this  is  called  the  forbidden  zone, there is a
teleporter  deep  in  the  dungeon. This teleporter leads to the bonus
dungeon.

What awaits you in this dungeon:

     -  Very powerful monsters with different elemental nullifications
including physical type attacks

     - Stronger version of the Final Boss

     - Boss Cameo from Atelier Iris 3