Magatama Idol Kaguya explains:Edit
"If you equip this Magatama, you will always have a stable nightlight for waking up early and going to bed late (results may vary). The light of this Magatama is very weak, so it is advised to store it in cool places with direct sunlight...Say what!? This sounds a lot like the instructions for raw food!! However, if you are struck by the faint rays of this Magatama, your skin will turn yellow with age, so watch out!!"