Mazda's proud rotary engine vehicle, the de facto successor to the 3rd generation RX-7. The RX-8 is notable in that it is a full-fledged sports car with a rotary engine and FR drive, yet it is a family car that can seat four adults properly. This was at the request of Ford, Mazda's parent company at the time of the sale. The marketing strategy is to have a four-seater that can be expected to sell in volume. This is because it was considered an absolutely essential condition for the development of new vehicles with rotary engines. In order to meet the conflicting requirements of a family car while achieving the performance of a full-fledged sports car, Mazda decided to adopt a unique mechanism called "Freestyle Doors," which allows the front and rear doors to open in a double-sided manner. And within these difficult constraints, Mazda's engineering team succeeded in giving the RX-8 very good qualities as a sports car. The turbocharger was eliminated from the 13B engine used in the RX-7, and the engine was converted to NA with numerous modifications to achieve higher rpm and lower fuel consumption. At the same time, the engine was made lighter and more compact, which greatly benefited the machine's turning ability and lower center of gravity. Mazda named the next-generation rotary engine with these improvements the 13B-RENESISE. 13B-RENESISE had less power than the turbocharged 13B engine in the RX-7, but it also improved on the environmental performance and fuel economy that had long been considered the weak points of the rotary engine. The complete improvement of the engine was also an indispensable measure to make vehicles with rotary engines comply with exhaust gas regulations around the world, which were becoming stricter every year. In 2003, the RX-8 made its debut. In 2004, the year after its debut, the RX-8 achieved annual sales of approximately 60,000 units, an unprecedented sales record for a sports car. However, it was not only in terms of sales and marketing that the RX-8 excelled. The RX-8's braking and cornering performance is regarded as the best among Japanese cars. The idea is to complete a car that is both a family car and a full-fledged sport car. Mazda's engineers have successfully achieved a seemingly impossible goal. In 2008 and 2010, the racing version introduced by Mazda USA won its class at the Daytona 24 Hours in the United States, beating out racing machines developed by Ferrari and Porsche.

In a world where warriors "samurai" wearing "Tsurugi" dominate the battlefield. Minato Kageaki, a man who calls himself an unofficial policeman, wears the red Tsurugi "Muramasa". He sometimes challenges a vile serial killer, and sometimes challenges the tyranny of military soldiers, and defeats them with his own power as the strongest warrior. But he never claims to be righteous. When he meets a demon, he kills the demon; when he meets a Buddha, he kills the Buddha." These are the words when he unite with "Tsurugi". He kills. Not only evil, but also good people who were oppressed by evil. ...... Is this surprising?　No, because it is not. Because the name of his "Tsurugi" is Seisyu Uemonnojo Muramasa. It is the same Muramasa who once turned the whole Yamato region into a hell.

The main character's sister-in-law who loves her dad too much and is out of control. She is a bit of an idiot. The true identity of the silver demon king, Ginsei-go. She is the biggest partner of the main character, Kageaki Minato, and a lovable sister-in-law. She is the daughter of Minato's own daughter. She wears the cursed Tsurugi "ni-sei Muramasa" and repeatedly commits massacres all over Yamato. In order to stop, Kageaki continues to pursue her in the third generation Muramasa. In the first round of the popularity contest, she lost to Kageaki Minato and dropped out of the third round, and in the second round she came in fourth place.