This conversation is just making me think that there could have been volunteer reapers for 9/11.
>During 9/11 Death Sensei got injured while on the job
>Says he's getting too old and might consider retirement
>The Mori family working as volunteer reapers
>Death Sensei spots a young Mori reaping, noticing her skill and realizing her potential
>Gives Mama Mori a pamphlet about a Grim Reaper program for Mori
>Mori declines at first but years later she asks if she can still sign up and finally begins her apprenticeship