The Red Sox reportedly are among three finalists for Japanese righthander Kohei Arihara:
https://www.mlbtraderumors.com/2020/12/report-padres-rangers-red-sox-are-finalists-for-kohei-arihara.html
Arihara is a year older than Yusei Kikuchi was two years ago when the lefthander signed with the Seattle Mariners. Their lines from Japan's Pacific League:
KA 129 G, 836 IP, 3.74 ERA, 1.21 WHIP, 3.23 K/BB. 817 H, 626 K, 194 BB
YK 195 G, 1010.2 IP, 2.77 ERA, 1.17 WHIP, 2.43 K/BB, 810 H, 903 K, 371 BB