To input a password, activate the heart icon in the upper right corner, then select the second second menu entry. A password-input screen will appear with two rows of five digits, like this:
00000
00000
The one that looks like this 0 will be blinking.
Pressing the A (left) button changes the value of the number at the current cursor location (the blinking location.) Each press increases the number by one. After 9, the number goes back to 0.
Pressing the B (middle) button moves the cursor to the next location to the right. When the cursor is in the right-most location in the upper row, B will move the cursor to the left-most location in the lower row. When you are done setting the number in the lower right corner, press the B button to signal you're done.
Pressing the C (right) button moves the cursor to the previous location to the left. When the cursor is in the upper left corner, press C button to cancel and exit back to the heart menu. When the cursor is in the left-most location in the lower row, C will move the cursor to the right-most location in the upper row.
Starting with a clear password entry screen, like this:
00000
00000
Pressing A eight times will make it look like this:
80000
00000
Then pressing B two times will make it look like this:
80000
00000
After that, pressing A one time, we should see this:
80100
00000
We're well along our way to inputing the password for the TamaDepa doughnut (80155 05372)
Eventually the password input screen should look like this:
80155
05372
Now, one final press of the B button and we're done.