A Joy Seed (しあわせのタネ Happiness Seed) raises the level of the Pokémon that uses it by 1, making them the Pokémon Mystery Dungeon equivalent of a Rare Candy. In addition to this, it is also known to increase the Belly of the Pokémon ingesting it by 5.

Locations in Explorers of Time, Darkness, & Sky

• Oblivion Forest (appears on 10F-24F)
• Treacherous Waters (appears on 16F-19F)
• Southeastern Islands (appears on 10F-24F)
• Inferno Cave (appears on 10F-29F)
• Zero Isle East (all floors except 20F)
• Zero Isle West (all floors except 20F)
• Zero Isle South
• Destiny Tower