He is a doctor and a German expatriate who operates a clinic in town whose hobby is creating zombies from dough whom he uses to do some chores or carry his equipment when he goes out. He assist Roman either by treating his injuries or doing some kind of CSI medical examination.   (Otaku-streamer Forum)

The stage is the close of the Edo period, an age when, not unlike our own time, both natural and man-made disasters left chaos in their wake. Manjiro makes a living helping the people of the troubled capital city, but behind the scenes, he also works in secret to take back precious belongings stolen from the people by unjust political powers and conspiratorial menaces. The people call him "Get-backer Roman."<br><br>
(Source: Crunchyroll)

Hans von Rubelt