Hello Takuji Tanaka, Thanks for this upload:

Package: japanese-otf [found] Type: silent [found] Version: 1.7b8 2020-11-14 Version number: 1.7b8 [was: 1.7b8]

Please remember that the version number must be increased when a package is updated.

Version date: 2020-11-14 [was: 2019-04-01]

Additionally, this new date is not found in the files. Could you please update files accordingly and re-upload the package again? Thank you, Erik Braun for the CTAN team