L and Light caught Kira but Light didnt get his memories of being Kira back. So L didnt die. Watari signed L/ryuzaki up for a special version of Wammys similar to a highschool or boarding school. L tricked Misa and Light into coming. Then the younger generation (Mello, Near, etc) show up. The Boarding/high school is the main part of the town. That and the headquarters where L and the other members of the task force solve cases
(If this doesnt make sense ask me and Ill try to explain it better)
