The Case Files of Jeweler Richard Novel Volume 3 was written by Nanako Tsujimura with illustrations by Utako Yukihiro.

College student Seigi works part-time at Jewelry Étranger, run by the equally handsome and capable jeweler, Richard. All sorts of people visit the shop: a couple looking for a ring for their thirtieth wedding anniversary, a college student who’s lost contact with her significant other, and a client looking for someone to attend a very special auction in their stead––an auction in which a man who knows of Richard's past is in attendance. What happens when Seigi and Richard's feelings clash in earnest for the first time?!