Successfully complete the game to unlock the "BGM" option that can be used while playing the game.
BGM Option
To unlock the BGM option you have beat the game. The BGM option can only be used in-game.
Brute Wing
Kill Chimarea while it is poisoned to get the Brute Wing.
Cut Quill
Kill Harupia while she is poisoned to get the Cut Quill.
Easy Entai
Recruit or create five new members. Put them all in your party at once. Unequip the weapon and armor they are wearing. Dismiss all five of the newly created people. Go to the shop, and sell the weapons and armor that you just unequipped. Both are worth 10 Entai each, for a total of 100 Entai. The fastest method is to create about fifteen new people at a time, unequip them all, sell the items, then repeat.
Red Claws
Kill Hellion with Death status (Issen, Climax) to get the Red Claws.
Red Spine
Kill Colossus without bashing it (no bash element attacks) to get the Red Spine.
Snow Bone
Kill Scylla in five or less turns to get the Snow Bone.
Town Crown
Enter the following password to get an item called Town Crown, which adds the following stats: HP +15, TP +15, All Stats +2.
After you defeat the 5th floor boss go back to where you met Kurogane and he willl give you the Trust Band. Go to the Explorer Guild and you will get the Beast class.