While not nearly as well known as Yamamoto, Shota Imanaga is another Japanese pitcher coming over to MLB that was only just posted yesterday. Given that the Red Sox may need to add more than one starter this offseason, Imanaga needs to be on Boston's radar as a guy that could really help the backend of the Red Sox's rotation while not costing so much as to prevent the team from acquiring another quality arm.
Imanaga's stuff isn't nearly as flashy and Yamamoto's as he is a command over stuff guy who throws his fastball in the low 90's from the left side along with a split changeup and a pair of breaking balls. He doesn't walk a ton of batters and still has found ways to miss bats over in Japan despite not possessing overpowering stuff. He is going to require a high eight figure deal in all likelihood over (probably) five years or so, but that is more than reasonable given the cost of good starting pitching in free agency these days.
However, Imanaga doesn't come without some risk. In addition to not have the raw stuff to overpower hitters which could be problematic when he goes up against MLB hitters, Imanaga is already 30 years old. We have obviously seen pitchers dominate in the league into their late 30's and beyond (see: Justin Verlander, Clayton Kershaw, and Max Scherzer), but a certain amount of caution needs to be exercised when it comes to how long of a deal should be handed out to a guy that already has some mileage on his arm and has yet to play in the majors.