It is a brand new adaptation. So, it will be starting from the beginning of the story, but they haven't announced how many episodes this season will run yet, so it is hard to say how far into the story it will get. One exciting bit is that the original voice actors for the main pair are returning for this adaptation. Premieres in April.
They haven't announced how many episodes this season is planned to run for, so who knows? I suspect that this project wouldn't be happening unless they planned on adapting a good chunk of the source. It's not like this series needs the promotional help of an anime to sell light novel volumes.