There’s nothing worse in video games that losing your save file. It’s even more annoying if the sane file is gone due to bug in the game. This is the case for Ni No Kuni.
Several members of the gaming press has noted of the bug and it could happen to anyone. The bug occurs when you encounter the wand quest during the 45 minute mark of the game. If you save your game at the start of this quest, your whole save file will be erased.
Ni No Kuni releases this week in North America and in Europe. Be sure to keep this in mind before you play the game. Hopefully Namco Bandai will fix this issue with a simple patch.
Source: Gaming Everything