This is a List Of Social Events that occurred as plot points in Code Lyoko.
In "Teddygozilla", there was a prom being set up. The first shot of the episode is The Kadic News reporting on it. In the initial timeline, Ulrich Stern was going to attend with Yumi Ishiyama. After the Return To The Past; he went with Amelia "Milly" Solovieff, due to her asking him. For some reason, this includes a competition for a Beauty Queen, for which Elisabeth Delmas was a contender.
End Of Year Dance
The "End of the Year" dance is the dance that appeared in "The Key". It appears that only couples could go inside, as in the background of a scene, Jim could be seen turning individuals away. None of the Lyoko Warriors, went to the dance although Odd came close, due to the fact that they had to go to Sector Five to retrieve Aelita's memory fragment. The dance is not seen or spoken of again in later episodes.