Manga by Mi Tagawa

Just when everything seems like smooth sailing for Senzou and Manpachi, trouble arrives on their doorstep. The ancient stone of destruction starts oozing miasma and as it does, some of Senzou's deeply buried past memories start to rise up — memories of “another” Manpachi who seems to have been Senzou's first companion. But how can that be when Manpachi is here with Senzou and the others right now...?