Episode 13 of the DN Angel anime.
When Dark goes to steal The Eternal Guide statue, a sealer placed by Satoshi causes Dark, Risa and Takeshi's souls to be trapped inside a stone. To rescue them, Daisuke has to travel into what appears to be the future with Towa. However, it may have just been an illusion of Daisuke's wishes, which is what occurred in a similar situation in the manga. While there, he stumbles upon someone special.