Gift Boxes is a move that puts gift boxes on the feet of the current team. When any of the characters lose all of their health, that character's gift box will disappear, and the character will have full health.
The following characters can use Gift Boxes:
Gift boxes is a very powerful move. If you want to make it the most effective it can be, I would recommend using a character that has Mimic Ball or using the chip Auto: Mimic. This way, you can revive dead characters and give those same characters a gift box.
Now, just because Gift Boxes is a good attack doesn’t mean your invincible. Worst-case-scenario, you fight Security and have no Neon Wall. Security then uses Alarm 5 times, wiping out all your gift boxes and just so happens to kill the character with Gift Boxes.
What I just stated is an extreme, but it should help you understand how important it is to always use a healing character alongside Gift Boxes.