Is this the third film or the fourth?

Mild-mannered Shizuya Kondo lives a normal life, occupied with his dreary office job as a women's underwear designer. But, he also happens to be the only son of the leader of the biggest criminal organization in the Kanto region... and when his father is murdered by a rival gang, Shizuya is forced to become the new head of his yakuza family! Working as a businessman by day and a yakuza boss by night, Shizuya finally begins to realize his true potential. But, things take an unexpected turn when Akemi, his secret office-crush, is suddenly kidnapped.

Quiet Don Volume 2

After the death of Sakamoto (Susumu Terajima), the boss, in a conflict with the Shinsengumi, chaos spread within the Kishugumi over who would take the next leadership position. Sawaki (Daichi Asai), the underboss who had been favored by Sakamoto and his wife, Ryuko (Mariko Tsutsui), was ousted from his position as a senior executive. Meanwhile, Shizuka, thinking that in order to continue his relationship with Akino, whom he cares deeply for, he must eliminate conflict in Japan and withdraw from the yakuza world. The proposal Shizuka made for this was outrageous! This caused shockwaves through both gangs, and Ryuko found herself troubled, lost in thought. Then came the fateful day—

Though Ryuko had decided not to perform the traditional oyako-sakazuki ceremony, which formally recognizes a parent-child relationship in the yakuza, Sawaki became the new leader of the Kishugumi. However, Ryuko was killed in a plot by Odata, and the blame was falsely placed on the Shinsengumi. Believing the Shinsengumi were responsible, an enraged Sawaki led the Kishugumi to Tokyo and declared all-out war on the Shinsengumi. While Shizuka maintained his silence despite the Kishugumi's assault, the Shinsengumi members grew frustrated... However, an incident finally pushed Shizuka over the edge! What will become of the Shinsengumi's future? Will Shizuka's desire for peace prevail? And what will be the outcome of his romance with Akino?

The Kishu clan loses its leader Sakamoto (Terajima Susumu) in a conflict with the rival Shinshu Clan, and a battle for succession breaks out. Meanwhile, Shizuya (Ito Kentaro), the head of the Shinshu Clan, puts the safety of his beloved Akino (Kakei Miwako) first and makes a proposal to the Kishu clan to avoid further conflict, but the situation deteriorates further.

Kondo Shizuka works at a design company by day and leads the Shinsen-gumi by night. Though a yakuza, he dislikes conflict and revitalizes his gang with fresh ideas. Months after the Onishu-gumi conflict, the new boss Kaifu poses a threat. While planning peace, Kaifu surprises Shizuka by proposing a negotiation. Displeased Onishu members hire legendary hitman J to kill him. Unaware, Shizuka meets Ayako, a high school girl who is a yakuza’s daughter. After surviving J’s attack with Inokubi’s help, Shizuka has three days to evade assassination before the peace talks.

J attacks Shizuka at home again, and even while hiding at Namakura’s, Shizuka is targeted. He realizes J has spared him multiple times. At the peace signing, J appears, but Omura is shot instead. Kaifu, angered, starts a conflict—but it’s a setup to frame Shinsen-gumi. Media exposure reveals Shizuka’s yakuza identity. When Ayako is attacked, she accidentally kills J. To protect her, Shizuka takes the blame and goes on the run.

The Shinsen-gumi–Onishu conflict escalates, causing defections. Naruto and Inokubi vow to prove Shizuka’s innocence, leaving Namakura and Hijikata in charge. They investigate while Shizuka hides with his boss. At the hospital, a scuffle implicates Shinsen-gumi, causing arrests and deaths. Seeing the situation and loyal members’ faith, Shizuka resolves to confront Onishu-gumi himself.

Shizuka decides to confront Onishu-gumi, joined by Naruto, Inokubi, and loyal members. Former Onishu members Namakura, Hijikata, and Gomada switch sides to Shinsen-gumi, strengthening their forces. In the ensuing war, Shinsen-gumi defeats Onishu-gumi, and Shizuka faces Kaifu in a final showdown. Victorious, he surrenders to the police, but Ayako clears his name. Shizuka returns to normal life, now more determined than ever toward the Unification of Japan.