Oda Teruyu (played by Shotaro Mamiya) who is drifting overseas risks his life many times.But each time, he survives the fatal situation thanks to an old key he carries with him.It is said that there are 99 keys in total.Huiyu travels around the world to find the remaining keys and pursue the mystery of the keys.

When Huiyou saw the news, he suddenly decided to return to Japan.Huiyou stared at the key in his hand, and the memory of his father came to his mind.

Fourteen years ago, I was taken to a camp by my father, Seiji (Koji Yoshikawa), who was serving as chairman of the Oda Group, one of Japan’s leading general trading companies.Under the starry sky, Seiji showed an old key to Huiyu and told him that it was a “devil's key” and that as long as you hold it, it will bring good luck.This is the fateful encounter between Huiyu and “Devil's Key”.

Terutomo returns to Japan and visits his father's company, now known as the Miyanouchi Group, which is taken over.

There she meets her late father's secretary, her trusted Ryuto Okamoto (Jun Hashimoto).

Huiyou tells Ryukin that “Devil Key” is related to mysterious property transfer cases that frequently occur in Japan.Thirteen years ago, her father Seiji was killed by a man (Kokichi Ozawa) who appeared behind the Devil's Key.Huiyu was entrusted with the “Devil Key” before he died, and escaped overseas with the help of Ryukin.

When Terutomo returned to Japan after 13 years, Ryukin was not the only one to welcome him.

Hatsu Saito (played by Tatsumi Tanaka) and Yuki Manabe (played by Kotone Furukawa) are good friends from the same junior high school. They developed the next generation of generative artificial intelligence and founded a venture capital company.The two people who had been worried about Huiyu who suddenly went overseas learned from SNS that Huiyu was in Japan.

Yuki immediately contacted Teruyu.When the three met again after many years, Chu, who had had friendship and competition with Huiyou, had an awkward attitude towards Huiyou's current state.When Huiyou returned home, he saw a familiar man's face.This was the man he saw on the news about the property transfer case overseas, and the man who killed his father 13 years ago.She hurriedly chased after him, but the man quickly disappeared.

The next day, Ryukin came to Huiyu's room.Liu Jin told Hui You that he had been investigating a series of property transfer cases.By chance, Yuki also came to visit.Then the doorbell rang.When they opened the door, they discovered the second generation of Maruko Mitsuhide (played by Kenta Suga) of the anti-social organization “Maruko Family” and his followers.

Maruko comes to steal Huiyou's “Devil Key”.In front of Teruyu, who didn't know the true meaning of the key, Maruko took out her “Demon Key”, slowly inserted it into the table and turned it.Then, a tornado appeared, and a giant beast appeared in front of me!