Bell Nuts are small, bell-shaped dry shells with a hard seed or other small ball inside. When the nut is shaken the ball creates a soothing rattle. They feature most heavily in episode 12.
Bell nuts are given as gifts at the Passing of the Year Festival, with the colour of the nut signifying a specific emotion or message the giver wishes to give the reciever. This tradition only takes place in the closing hours of the old year, though it may be acceptable to give them at other times - in episode 12 Reki gives white bell nuts to Hyouko and Midori a week early.
Bell Nuts are grown in the months leading up to the Passing of the Year Festival, and during that time different materials are added to the soil to give them their distinctive colours. The nuts are ready to be bought at least a week before the festival.
Colours and Messages
Each colour of bell nut is intended to pass on a different message.
- Thank you for taking care of me.
- Love (although Reki says it would mean You are stupid!.)
- Thank you and good bye.
The meaning behind these colours can be carried without bell nuts - in episode 12 the haibane from the Abandoned Factory give their final message to Reki by setting off yellow fireworks. Reki returns the favour by sending them a yellow cake.