This is actually two games, which were released separately in Japan. They are a spin off of the Ace Attorney series, set in an alternative Victorian england. You play as a Japanese student who unexpectedly becomes a defence attorney after stowing away on a ship to England to join his friend who was travelling to learn how justice works in England to help develop the system in Japan.
The games are both quite long, and so combined this is a huge game with a lot of cases. They all end up relating to each other though, and it actually makes a lot of sense them being joined together. The ending does actually setup a third entry, but so far there is no news whether that is going to happen.
One of the main characters is Herlock Sholmes, who in the Japanese version is literally just Shelock Holmes. He’s a very funny character, who seems overconfident and bumbling but later on it becomes clear that he knows a lot more than he lets on.
There are two major new mechanics in these games. One is that England has a jury system, at any time in the trial the six members of the jury can declare that they’ve reached a verdict. It’s on you to show any contradictions between the positions that they take. The other is deductions, which take place during the investigation sections. This is when you arrive at a new scene, and Sholmes declares that he’s figured out what has happened. He always reaches incorrect conclusions however, and it’s on you to redirect his statements to figure out the truth.