A revision to Japan's Unfair Competition Prevention Act has reportedly introduced criminal penalties for reselling software product keys without permission, distributing save-game editors, and offering to edit save data as a service. Speculation is rampant as to how broadly the data-editing ban may apply.
http://mmofallout.com/japan-criminalizes-editing-save-games-punishable-with-jail-time-and-fines/
http://www.gamasutra.com/view/news/333748/Japan_has_made_reselling_digital_game_keys_illegal.php
(Score: 3, Interesting) by shortscreen on Saturday January 05 2019, @10:20PM
Several Japanese news sites are carrying this same headline and article text: https://news.biglobe.ne.jp/it/1220/nlb_181220_5434014301.html [biglobe.ne.jp]
It notes that the Cyber Gadget save editor has been withdrawn and raises the question as to whether the Unfair Competition Prevention Act was the reason. Cyber Gadget did not confirm whether that was the reason. There's no additional information.
The ACCS link lists the three things mentioned in (my) TFS. It links to this page which appears to have the complete text of the law, including a 2018 amendment: http://www.meti.go.jp/policy/economy/chizai/chiteki/kaisei_archive.html [meti.go.jp]
The legalese is way beyond me and since they are PDFs I can't do a search or copy-and-paste words into the dictionary :(
It's weird that I can't seem to find any commentary or reaction to the passing of the law.
Here is another brief article in English: http://www.nintendolife.com/news/2019/01/it_is_now_illegal_to_sell_unauthorised_game_keys_in_japan_save_file_editors_also_banned [nintendolife.com]