[x] If you are reporting an issue that affects glyphs for characters for a particular region or regions, did you verify that the characters are within the supported scope of the region or regions? This generally means GB 18030 or Tōngyòng Guīfàn Hànzìbiǎo (通用规范汉字表) for China, Big Five or CNS 11643 Planes 1 & 2 for Taiwan, HKSCS-2016 for Hong Kong, JIS X 0208, JIS X 0212, and JIS X 0213 for Japan, and KS X 1001 and KS X 1002 for Korea.
[x] Did you thoroughly search the open and closed issues to avoid reporting a duplicate issue?
[x] Did you go through the official font readme file to better understand the scope of the project, to include the Known Issues section at the very end?
It does contain Japanese, but "Japanese" isn't in the name anywhere. If you have the SuperOTC installed you should see either Source Han Sans ExtraLight or源ノ角ゴシック ExtraLight in the font menu.
Prerequisites
Description
superOTC doesn't seem to contain Japanese