JustCo lists flexible workspaces in Shibuya, Shinjuku, Marunouchi and Aoyama. Its private-office product provides a furnished, lockable room with 24/7 access and business-address services.
The official private-office page says terms start from one month, but it does not publish a numeric Tokyo office fee. It describes a business address and mail handling without explicitly confirming that every Tokyo address may be used for company registration.
The availability of a dedicated room is relevant when comparing physical workplaces for a Business Manager application, but JustCo does not claim that its offices meet immigration requirements. Confirm registration permission, the lease wording, exclusive use and the exact room configuration before signing.