Okuhara's women's singles 11-21, 21-17, 21-24 win over Sung Ji Hyun proved to be vital for Japan, helping them stay in the contest and setting the stage for the women's doubles and mixed doubles pairs to ensure Japan made their third recent major team event final.
Korea started well, with men's doubles due Lee Yong Dae and Yoo Yeon Seong giving them a 1-0 lead by beating Hirokatsu Hashimoto and Noriyasu Hirata.
The Koreans scarcely put a foot wrong, getting more and more dominant as the match progressed and ran out 21-18, 21-16 winners.
Takuma Ueda replaced the injured Kento Momota in the men's singles for Japan and gave Son Wan Ho a run for his money but in the end lost 21-9, 22-20 to a very in form Son.
Japan's women's doubles pair of Misaki Matsutomo/Ayaka Takahashi were all over Jung Kyung Eun and Chang Ye Na and ended up winning 21-17, 21-8.
Korea looked to have the advantage in the final mixed doubles match with Japan fielded the scratch pair of Kenta Kazuno and Ayane Kurihara against world No.8 duo Ko Sung Hyun/Kim Ha Na.
Ko and Kim were blown away 21-14, 21-15 by the new combination as Japan clinched its final place and will face China on Sunday.