Housekishou Richard-shi no Nazo Kantei

When Japanese college student Seigi Nakata rescues a handsome young jewelry appraiser from a group of drunken assailants, he gets more than he bargains for! The appraiser is Richard Ranashinha de Vulpian, a brilliant and mysterious British jewelry expert. Seigi hires Richard to appraise a ring left to Seigi by his grandmother…and the adventures are just beginning. Together, they unlock the secret messages hidden in the hearts of jewels—and those who possess them.

(Source: Seven Seas Entertainment)