Housekishou Richard-shi no Nazo Kantei

The series revolve around two people entwined with mysteries and always finding themselves solving them. In Kyoto Teramachi Sanjou no Holmes, the central objects are antiques while in Housekishou Richard-shi no Nazo Kantei are gems / jewelries. 

Both have that same mystery genre that involves anything that has value, where one was more on antiques , while the other deals with Jewelries and precious stones.....  

-One of the MCs is a shop owner and the other is a part-timer -The shop owner teaches the part-timer various things -Educational in some way -Slight Romance/ Bromance -Relaxing Vibes -Solves mysteries -The duos always protect and save each other'  

Similarities: 1. same "case file" thing that involves things with value. 2. Same situation where it involves one genius at the helm and one that takes some errrr......... an apprentice that needs some improvements. 3. Same, mystery and slice of life genre, with some rather subtle romance on the sides.... Dissimilarities: 1. One was more on the value of Antiques while the other is more on the precious stone business. 2. Genius MC in one anime got his start by being a scum himself, before going legit, while the genius MC in another anime got his start from working in the antique shop and doing countless research while studying in a prestigious university. 3. Romance element in one anime was more like a yaoi kinda thing while in the other was more of just the usual.  read more 

Both with an apprentice novice with the subject (arts or jewelry) delightful to learn more and a cool good-looking tea person that masters the subject and works a shop. Both Anime are filled with a relaxing vibe and a lot of culture and really nice character's personalities and development. Both amazing slices of life that shares a similar message to the watchers.  

I think the greatest coincidence between the two shows is how their japanese protagonists look alike. Eiji (Banana Fish) and Seiji (The case Files of Jeweler Richard, hereinafter The Case Files) have a similar appearance and personality that in the end causes both to be involved in the affairs of their respective foreign partners. In addition, in both there is a certain Bl air without becoming Bl but with certain doses of fanservice. Now, if we accentuate the differences The Case Files is much calmer in comparison, with self-concluding and somewhat educational chapters since with each chapter you learn about precious stones, while Banana Fish has a unique story throughout its chapters. Anyway, if you liked one of the two I recommend you see the other. read more 

the two main character take risks to help each other and its very heartwarming. they care very deeply for each other. in many ways, ash and richard are very alike, and eiji and seigi too. of course, they are not exactly alike but examples would be bits of their personalities and backgrounds.  

Pretty, blonde white boy x Sweet Japanese Boy - this time with less trauma!! 

Both anime have male duos working together to solve mysteries. The case files of jeweler Richard is about jewellery appraisal and solving various requests (all associated with jewels), whereas the millionaire detective - balance:unlimited is about a pair of detectives resolving crimes with the use of a bank account with an unlimited sum of money. There are similar dynamics between the characters of each series with one of the duo being high-class and elegant and the other being more lively and clumsy. Both of the anime have similar art styles and are visually pleasing. 

The relationship between the two main characters are similar 

Okay these two are probably the most similar cause they deal with a BUNCH of money. But still, French, Blonde haired, blue eyed white boy with a nice face x guy from Japan.  

If you like peaceful anime, this is one of them like Bartender. Every episode includes them solving problems just like the Bartender, but not with drinks It's chill and short, can't find anything to watch after watching Bartender, but this has a similar vibe to it.