Kozutumi is a file transfer service from Heartbeats Inc. designed to help organizations move away from PPAP (the practice of sending password-protected ZIP files by email). Every transfer includes timestamp-based content certification that gives sent and received files legal evidentiary value, and a send cancellation function lets senders revoke access before the recipient downloads.

Paid plans include automatic cyber risk insurance from Tokio Marine and Nichido Fire Insurance, covering information leak incidents without requiring a separate policy. Send and receive history along with operation logs are retained long-term, supporting audit compliance and tax investigations. The service also integrates with Microsoft Teams for everyday workflow access, and the service holds ISMS and ISMS Cloud Security certifications. A free tier is available for small teams to get started.