Her old life of wandering the endless streets has now ended and her new life as Kameko Mai has begun. Known by the letter P, she is hopeful successor of the world's greatest detective, otherwise known as L. Adopted into Wammy's House, she meets another hopeful successor that goes by 'Backup' or 'B' for short. As the two work together on their first dangerous case, P goes missing. Can she be found? And if she is, will this experience mean she's not up to the job of filling L's position?

What will you get if you pair a reckless, impulsive, dramatic young lady and London's corinthian and master conspirator in an obscure engagement? Simple: the bride to be will try to flee and the groom to be will do what he does best, to seduce and conspire!