Catch and release for bass fishing in Lake Biwa is a bit of a gray area. According to the video context from "The Ugly Truth About Japan's Bass Fishing Scene! (3 Things You Didn't Know!)" by crazybassfisher, technically, you are supposed to kill the bass you catch in Lake Biwa because bass are considered an invasive species. However, in practice, many anglers in Japan, including those fishing at Lake Biwa, often release their bass back into the lake off-camera. This practice is done discreetly because showing the release of bass is illegal.
The reason behind this regulation is that the government and local farmers are concerned about the impact of bass on native fish species and the ecosystem. Despite this, the lake's abundant forage allows the remaining bass to grow quite large, which is why Lake Biwa is known for its giant bass.
So, while catch and release is technically not allowed, it is commonly practiced by anglers who wish to preserve the bass population for future fishing. If you plan to fish at Lake Biwa, be aware of these regulations and the local customs surrounding them.
If you have any more questions or need further clarification, feel free to ask!