Tantei wa mou Shindeiru is one of the hottest light novel titles at the moment in Japan. For good reason, the series has a rather interesting set up which the title kind of spoils. The main character went into many adventure with the detective but one year has passed since her death at the start of series. The main character retreated to his normal life.
However, events unfolds that means he finds himself drawn to his past life which he subconsciously missed. This series is interesting, the characters are interesting each with their own motivations and thoughts and interactions are quite fun and the overall plot whilst a bit cheesy its not bad. And perhaps the biggest edge for this novel is how it can often drifts to the past because it is incredibly important for the plot as the title suggests.
The studio handling the animation will be Engi, the ones behind the Full Dive VRMMO series from this season. It is overall a new but promising studio and the promotional videos look decent. The director is not too experienced but his past works as episode director seems decent and the rest of the staff is good too. So, I expect this one to play out really well.