We have a block of hotel rooms reserved for conference attendees.
You can purchase train tickets of the entire journey to Matsumoto at the airport JR ticketing desk.
You can purchase a ticket of Azusa limited express at the Shinjuku station.
From Shinjuku neighborhoods
From Tokyo station neighborhoods
From Kansai area and Nagoya
Check https://visitmatsumoto.com/en/access/ for more access guide.