text garbling from AppleScript to Numbers

I want to write Japanese text with AppleScript in Numbers.

but the text was garbled when outputting Japanese to Numbers with AppleScript.

I already has attempted to cast the text as String, Unicode text or «class utf8».

but all of them failed...

(For example it changes like this: 価格 -> ??, 量 -> ?, 合計 -> ??)

Please tell me how to output Japanese from AppleScript to Numbers correctly!!