When a series opens with a scene where blood is found within an empty carriage, the freelance investigator finds a mysterious map inside and starts off on the wrong foot with the official detective, my curiosity is piqued and I have to carry on watching. When it appears that both leads are more closely involved with the mystery than expected and the plot thickens, I have to carry on watching. I like mysteries, so might be biased.
The subtitles are spotty, but enough to get the gist of the story, so as long as you don't mind genders being inverted and people being called "it", it's easy to fill in the gaps.
Look, it won't win any awards, but if you want to pass a lazy afternoon watching a bromance revolving around a mystery with a basic plot, and a lot of typical tropes, go for it. I have seen much worse and the two leads are nice-looking men with lovely smiles (yes, both smile, but one hardly).