Devil For A Diary

What if one day , you find a diary which will grant all of your wishes ?

Sora , a 16 years old found a diary in his mom's dresser. Upon writing some wishes in that diary, they came true . But what could probably go wrong with a wish granting diary like that . Why does he referred it to as a devil? What was the mystery behind it and most importantly -

Why was it in his mom's dresser?

Story editor @QT_Rox