In episode 52, Yoko Sakaki plays this card in her duel against Yuya Sakaki. She activates this card increasing the ATK of all cards by 100 for every monster on the field. Since there are 3 monsters, all monsters gain 300 ATK until the end of the turn. In the following episode, Yuya targets this card in Yoko's Graveyard with "Magical Sky Mirror", treating this card's effect as the effect of "Magical Sky Mirror" since it was activated last turn. "Magical Sky Mirror" increases the ATK of all cards by 100 for every monster on the field. Since there are 4 monsters, all monsters gain 400 ATK until the end of the turn.
After the duel ends, Yoko gives this card to Yuya since Yusho Sakaki told her to give it to him when she felt he had a need for it.
This card appears in a flashback in episode 52 and 53 where Yoko remembers Yusho playing this card to save her from a rival gang.
In episode 56, this card appears in a flashback when Yuya remembers Yoko telling him to bring smiles to everywhere he goes.
During episode 110, it is revealed that Aster's torn copy of Smile World was once Yusho Sakaki's, who used it to defeat the latter in an action duel. Yusho offered Aster the card, but a Aster ends up tearing it in half due to his confliction with Yusho and the Professor's teachings.
During episode 111, Yuya uses his copy of Smile World to defeat Aster Phoenix in a duel, comboing it with "Brave-Eyes Pendulum Dragon" and the Action Card, Miracle Fire.