Sponichi has published a detailed account of the contract Boston offered to Junichi Tazawa. The article also quotes "They want me to come over, and I understand how I can develop. I feel like it's a good team". Nikkan Sports is reporting that Tazawa has already decided on the Red Sox, and says that he'll be able to officially sign at the beginning of December.
The dollar figure is a little surprising - there were numerous reports of a $6M offer earlier in the day. Maybe there is a bonus or incentive package that was left off of this report. We'll learn more over the next couple days.