She was frozen. Killed. Lake Biwa is a catch and kill only lake for largemouth bass. No LMB caught in Lake Biwa may be released.
I live in Japan and fish Lake Biwa regularly. Bass and bluegill are treated as invasives in certain prefectures (states). Mainly areas where they have an impact on the native ayu, wakasagi and trout populations. By the letter of the law, you must kill any you catch, but I've never seen a bass retained on Biwa by any angler other than to weigh in at a tournament, and they were released afterwards. To counteract the fact that no one abides by the law, the government started electrofishing during the spawn and removing the fish. The lake seems to still have a decent population and there are giants every year, but I have been told that it was an incredible place in the early 2000s.