The Ambition of Oda Nobuna

Yoshiharu Sagara finds himself in the Sengoku era and his life saved by the sacrifice of Hideyoshi Toyotomi. When he saves a teenage girl from enemy soldiers, he is surprised to discover that the girl is a female Nobunaga Oda named Nobuna Oda, the Daimyo of Owari. Furthermore, he also discovers some of the historical warlords of this era are female as well. As a reward of saving her life, Nobuna makes Yoshiharu her retainer but she, including her other servants Katsuie Shibata, Nagahide Niwa and Inuchiyo Maeda, are skeptical of his claims that he is from the future. Nevertheless, he vows to take over Hideyoshi's role in helping Nobuna. Meanwhile, the Daimyo of Mino, Dōsan Saitō, calls for a meeting with Nobuna over an alliance. Dōsan's servant Mitsuhide Akechi attempts an ambush on the Oda delegation but her plans are thwarted by Yoshiharu who convinces Nobuna to have her troops prepare their rifles. During the meeting, Nobuna reveals to Dōsan of her dreams for Japan and Yoshiharu reveals to him how will history view him in the future if he accept the alliance. Impressed by Yoshiharu's speech, he agrees to ally with the Oda clan by making Nobuna his heir.

Yoshiharu gets into trouble after he hits Nobukatsu Oda, Nobuna's younger brother after the latter insulted his sister. Nobukatsu demands his head as punishment but Nobuna can save Yoshiharu's life if she makes him a general but he must first prove his worth by assigning him to gather 8,000 koku of rice in a week. Using his marketing strategy of buying low and selling high, Yoshiharu manages to gather enough gold to buy the rice four times more than he was tasked in a week thanks to his ninja servant Goemon Hachisuka and Inuchiyo's help. However, Nobukatsu launches a rebellion after being convinced by his advisers that his sister is not fit to rule the clan. But Nobukatsu's rebellion is quickly and peacefully stopped after Nobuna's forces surround Nobukatsu's castle where Yoshiharu and the soldiers shout rally cries that scares Nobukatsu into submission. Nobuna attempts to kill Nobukatsu to set an example to others but Yoshiharu forces her to stop as he knows she still loves her brother and doing so will make her ruthless just like Nobunaga. Convinced, she forgives her brother who in gratitude, swears to never to rebel again and changes his name to Nobusumi Tsuda. Nobuna thanks Yoshiharu for what he did and makes him swear his loyalty to her.

Dōsan's son Yoshitatsu launches a coup d'état against his father for allying with Nobuna. Despite Nobuna's wish to send reinforcements, everyone knows they cannot do it for it will allow the Daimyo of Suruga, Yoshimoto Imagawa, the opportunity to invade Owari. Meanwhile, the Daimyo of Oumi, Nagamasa Asai meets with Nobuna to propose an alliance between their clans which will allow her armies to help Dōsan while his armies protect her borders against the Imagawa clan in exchange she marries him. However, Yoshiharu and the others loathes Nagamasa as he threatens to ally with the Imagawas if Nobuna refuses and he does not care about her feelings and is only interested with the benefits he gains as her husband. Yoshiharu, Katsuie, Nagahide and Inuchiyo convinces Nobuna to decline his offer. Not soon after that, Mitsuhide arrives with Dōsan's daughter Kichō, who Dōsan's entrusts her well being and his dreams to Nobuna as he prepares for a last stand near a river. Katsuie is forced to knockout Nobuna to prevent her from doing anything rash. Not wishing to see Nobuna sad over Dōsan's death, Yoshiharu, Goemon and a small group rescues Dōsan and his men as they escape to Owari from Yoshitatsu's forces through the river. Despite Yoshitatsu attempts to kill them, they are force to retreat when the Oda army saves Yoshiharu's group. As Nobuna berates Yoshiharu for his foolishness, everyone is soon informed that Yoshimoto and her army have invaded into Owari.