With his condition rapidly deteriorating, Takuboku tasks Kyousuke with tailing a suspicious man they saw at the church. Takuboku is certain that a single criminal, Accuser X, is the true culprit behind the string of crimes involving accusatory letters which have exposed various social issues. Who is Accuser X, and what is that person's true objective?
The true culprit, 
whom I have named Accuser X,
،القاتِل الحقيقيّ والذي سمّيتُه المُتّهِم أكس
Der wahre Täter, den ich Ankläger X getauft habe,
Si le malfaiteur,
que j’ai nommé dénonciateur X,
Se pensiamo che il vero colpevole,
che ho battezzato Accusatore X,
O verdadeiro culpado,
que eu chamo de acusador X,
Настоящий преступник, 
которого я зову Обвинитель Икс,