I don't think that sequence is a......correction a quick check of my US Mailbag of Manga reveals that it is currently available as a TPB the one you're looking for is Vol #16 'Mystery Child'.
--Rod.H
A proud non-believer in the Viz non-US sales policy
"Our local Borders has a shelving unit full of new & recent printing/title Viz TPBs"
--Rod.H
A proud non-believer in the Viz non-US sales policy
"Our local Borders has a shelving unit full of new & recent printing/title Viz TPBs"