Résumé en anglais de la partie de Kiryu:
The girl is Mayumi, daughter of Madarame Tadashi, head of the Yamakasa-kumi in Nagasu.
Madarame was asked by Dôjima Daigo (current head of the Tôjô Association) to look after Kiryû in secret, and is responsible for getting Kiryû his job with the taxi company. He also sent Mayumi to keep tabs on Kiryû (that's part of the reason why she keeps showing up).
Madarame meets with Daigo to discuss an alliance deal, but Daigo meets with him in an unusual manner by taking a drive with him and tells him he suspects Aoyama, his lieutenant, is actually plotting against him and asks Madarame's help to disappear for a while. Aoyama visits Madarame to sign the deal in Daigo's absence and shoots him, but blames it on Kiryû when Madarame's lieutenant, Yahata, shows up.
Because Daigo warned him, Madarame wears a bulletproof vest and is just injured. That's why Mayumi takes Kiryû to meet him when he spurns her affections after she sees the Tôjô crest when Morinaga and Aizawa show up wounded at his apartment.
In order to prevent a full-out war, Madarame wants to disband his group and gives a writ of his intentions to Kiryû. Kiryû looks for and finds the Yahata hangout, delivers the notice, but tears it up. He wants them to rally and protect the area rather than disband. In order to prevent the coming war, he makes a deal with Aoyama to defeat the Tôjô army single-handedly (presumably to keep them from invading the territory).
Aoyama is used to his role as director or general of fighting and does not want to fight Kiryû directly or honestly, so that's why his friend Watase, who is currently head of the Ômi Alliance, is like "man up!" After being beaten up a bit, Aoyama is shot by Morinaga so he won't talk about the big conspiracy in the game's plot. Morinaga also says he killed Aizawa and buried him in the woods.
Kiryû seems to think all is well, but then the Osakan police detective, Serizawa, shows up and tells him to listen to the news on the radio, which is about Majima's death. Kiryû then decides to go to Tokyo and take care of business.