There is a great item, perhaps the best one in the game, hidden on the first floor of the labyrinth. It is the Happiness Ring, which gives you 10x experience and Gold for defeating monsters. Here is how to find it:
Step 1: Access the camp menu, and select the "Access Config" option (it's the top option on the second page)
Step 2: Select "No"
Step 3: Do the "Access Config" option and select "No" two more times. (You will know you are on the right track if a new menu item "Key Config" appears. When this happens, you only need to do "Access Config" one more time.)
Step 4: Go to the first floor of the labyrinth and move to this square:
Step 5: Face left and press enter.
The ring will definitely save on some level grinding! ;-)
If you play Toushin Toshi 3.9 Ver.5.32, you can rename the protagonist's name by pressing Esc with the right timing on the Title Screen. A window for renaming will be opened and after pressing ok and beginning a new game, the name of the Protagonist will change.
There are three girls trapped in mirror fragments in this. Of the three, one is required to get from chests on floor 8, but the other two are random drops from enemies on specific floors that give rewards when found. Each floor has two pieces of the mirror that can drop and you need six total. Each girl counts as two cgs. Girl 1 is found on floors 1,2, and 3 and gives 2,000 experience when found. Girl 2 is found on floors 5,6, and 7 and gives 3,000 experience when found.