There’s more to do at the Climax Theater than the Charisma Classroom quest. The PSP version on Persona 2: Innocent Sin includes a full blown quest editor.
A screenshot from Famitsu shows a player fixing NPC characters. It appears the maximum number of NPC characters you can set is ten and quests can take place in St. Hermelin High, the setting from Shin Megami Tensei: Persona. Other screenshots show dialogue editing and the event edit screen where you can pick a reward for completing a quest. User generated quests can be played at the Climax Theater.
Famitsu and Atlus are working together to create an original quest for Persona 2: Innocent Sin. The magazine also mentioned another side story "The Persona Thief." During a dream, you get a request from a nameless soul to investigate the "Heart’s Rest." When you arrive at Karukozaka High School, the setting for Shin Megami Tensei If…, you notice students at the school have lost their aspirations for some reason.
Persona 2: Innocent Sin is slated for release on April 14 in Japan.