I really don't like debugging but i'll tell you about it anyway. If you debug your tama you can make it grow faster and choose which character you want. It is very tricky and risky.NOTE: If you don't want to risk your tama or break it do NOT do this. So lets get to the "actions" of debugging. You will need a very tiny star screwdriver a soft led pencil and your eyes.
Step 1: Turn your tama around and do as if you are taking out the battery to replace it. Step 2:Take the battery out and unscrew the 4 tiny screws.Take it apart carefully. Step 3ut the battery in the spot where it is supposed to be and look below it to the left you will see 2 semi cirles. Under them should say 'debug'. Step 4: Color the semi circles with the led pencil carefully. Then put the tamagotchi back together and press reset. You should be able to choose a character now.
Want To un-debug your tama? Simple. You will need a soft/kneeded eraser for this and a tiny screw driver.
Do steps 1 & 2 from the above. Take the eraser and carefully erase the led off the 2 semi circles. Put the tamagotchi back together like before. Your tama should be back to normal.
There are not really any benefits except that the tamas grow up very quickly. Most people who debug do it because they are bored of regular tamas, or they just want to see all the characters without waiting for them to grow the slow way. There are also some characters that you can ONLY see by debugging. I guess Bandai decided not to use them in the finished toy for some reason.
If you decide to try debugging, you need to be really careful, and also know that there is a chance you can wreck your tama for good. You should read up on it first, before trying.