Good and centralised location surrounded by JR station and Tokyo Metro station. 7-11, Sunkist, and Family Mart are nearby too.
There is a tricky situation as to which door to open when I was there for the first time. The host was there to guide me. In reality, first digit of three numbers is the floor you are on. Once you are on that floor, turn to the left from the lift. You can open unlocked door and you will see the room number on each door inside.