- At dawn on 19 May 1560, Oda Nobunaga (Amami Yuki) orders Shibata Katsuie (Nakamura Shido) and the rest to depart for war. Bearing down on them is the army of Imagawa Yoshimoto (Mitani Koki) who was reputed to be the most likely ruler of Japan at that time. Nobunaga has a mere 2,000 troops in contrast to Imagawa’s 50,000-strong army. It was campaign that caught Imagawa’s army off guard by the deliberate circulation of a rumour about the surrender of Nobunaga’s army, and the use of Kinoshita Tokichiro (Iseya Yusuke), later Toyotomi Hideyoshi, as well as others. Imagawa’s army was trapped in the narrow valley of Okehazama and threw them into confusion. Imagawa himself was killed by Nobunaga. Through the Battle of Okehazama, Oda became a household name. But Nobunaga had a big secret. In May 1534, the child that Dota Gozen (Takahata Atsuko) had was a girl. Afraid that a boy that a concubine gave birth to would be made the heir, Gozen decided to raise her girl as a boy. This girl would be the future Nobunaga...
Her father Nobuhide (Nishida Teruyuki) learnt the truth after it was known to the world that Nobunaga would be the Oda family’s heir. Nobunaga is brought up by Hirate Masahide (Hiraizumi Sei). However, she is no match for her younger brother Nobuyuki (Kaku Kento), who is three years her junior, in military arts because she is a female. At the battlefield after the first campaign, Nobunaga entreats her father to make her die in this war and let her live as a female. However, he rebukes her, telling her that it is God’s will that she be the heir and unify the whole country … … And so, Nobunaga hides the fact that she is a female and lives as a male.
Two years later, talk of marriage between Nobunaga and the daughter of Saito Dosan, Ono (Koyuki). Nobunaga reveals her secret to Ono who cannot hide her shock. But Ono chooses to marry Nobunaga rather than continue to be a tool for an alliance. Then Nobuhide dies, and after that Hirate commits suicide leaving behind a note stating their wish that she create a peaceful world. With renewed resolve, Nobunaga kills Nobuyuki who has come to assault her in order to grab the reigns of the clan. She vows to unify the country and bring peace. Forming an alliance with Matsudaira Ieyasu (Fujiki Naohito) who broke away from the Imagawa family after the Battle of Okehazama, Nobunaga captures Mino seven years after the death of Saito Dosan, changes the name of the place to Gifu and relocates her residence. While she is searching for a route to proceed to the capital of Kyoto, Katsuie advocates attacking the Azai family in northern Omi, but Hideyoshi contends that Nobunaga should make peace. Hideyoshi succeeds in making this possible, but incurs Nobunaga’s displeasure when he asks for her sister Oichi (Nagasawa Masami) as his reward.
One day, Nobunaga falls ill. Because her secret will be leaked if she seeks a doctor’s diagnosis, Nobunaga is transformed into Ocho, a lady’s maid, by Ono and Oichi. The three of them are walking in the castle town when Ocho is suddenly struck by a horse on a rampage and loses consciousness. A young samurai who had witnessed the whole incident runs over to Ocho to tend to her. He is Azai Nagamasa (Tamayama Tetsuji) whom Hideyoshi had invited to discuss an alliance with the Oda clan. On a later date, Nobunaga and Hideyoshi visit Azai Hisamasa (Yamaji Kazuhihro) and Nagamasa at Odani Castle. The two clans are about to exchange pledges of alliance, but Nobunaga, who has been uncharacteristically observing Nagamasa talk ambitiously, abruptly stands up. She calls off the negotiations, returns to Gifu Castle and shuts herself away in a room. Neither Hideyoshi nor Katsuie can understand Nobunaga’s actions. However, Ono tells Nobunaga that it is because she has fallen in love with Nagamasa … … Later, Nobunaga meets Nagamasa alone and lets him in on her secret. Unable to wed Nagamasa even though she loves him, Nobunaga attempts to marry an unsuspecting Oichi to Nagamasa instead. The destiny of a female in the Sengoku period is to live as a tool for alliances.
It is Oichi’s long-cherished wish to do good for the clan, and so she gets married to Nagamasa. At that moment, Akechi Mitsuhide (Uchino Masaaki), an envoy of the Ashikaga shogun visits Nobunaga. This man would be a person who would greatly influence her destiny. Nobunaga goes on to invade the Asakuras of Echizen, but is forced to retreat because of the betrayal of Nagamasa. While withdrawing, Nagamasa, who has made an enemy of Nobunaga, is troubled by Nobunaga’s fear that her secret would be made known to the world and Ocho’s sadness to be betrayed by the man she loves. Nobunaga barely returns to Gifu with her life. Ono advises Nobunaga that Nagamasa needed to beat a strong man like Nobunaga in order to win fame and will not divulge the secret.