The Dream Gems are bright, colorful gems in Yoshi's Crafted World. They are part of the Sundream Stone and give it the power to grant wishes. There are five gems in all, each a different color. The colors are blue, orange, magenta, green, and yellow.
At the beginning of the game, many Yoshis are seen playing around the Sundream Stone, when suddenly, Kamek and Baby Bowser appear and try to steal the stone. In the struggle, the Sundream Stone becomes angry and sends everyone flying, freeing all the Dream Gems and scattering them across the lands. When the Yoshis come to, they discover that they are in a darkened forest, and that the Sundream Stone has lost all of its Dream Gems. One of the Yoshis decides to set out to find the Dream Gems, while the others stay to guard the Sundream Stone.
For most of the game, the Sundream Stone rests in the forest, guarded by the other Yoshis. When each Dream Gem is recovered, a Yoshi brings it to the forest and places it back on the stone. As Dream Gems are brought back, the Sundream Stone regains color, changes its expression, and brightens the forest more.
When the Yoshis find the fifth and final gem, Kamek swoops in and takes both the Green Dream Gem and the Sundream Stone. He places the gem on the stone, allowing it to grant Baby Bowser's wish for a large robot. After The Great King Bowser is defeated and destroyed, Kamek uses his magic and the magic of the Sundream Stone to transform Baby Bowser into Mega Baby Bowser.
Once Mega Baby Bowser is defeated and shrinks back to his normal size, Kamek flies away, and the Yoshis discover that the Dream Gems have been taken off the Sundream Stone again. They place the gems back on and dream of a way to get back home. The stone responds by creating a large craft rocket ship, which takes them all back to Yoshi's Island.
There are five gems in all, each a different color. Each gem must be recovered by defeating a regular boss in a boss level - defeating a mini-boss will not recover a gem.