Technically no story intro here; you're tossed directly onto the wharf. A nearby pay phone serves as a save point, and the dock has five guys around it you can talk to. No action yet, though; just head toward the ship and up its stairs. Toward the bow of the ship is a coin locker key. After you snag it, find the cabin, and enter.
Fuma is in a bed with an IV attached, but he's in good spirits and decent health. He sounds tired, but he's got the energy to talk about everything that's going on.
Turns out that Mizuki doesn't exist, in a sense. Yumi and Mizuki are the same person; "Mizuki" was just an alternate identity. Also, Haruka's father is Jingu, the man from the MBI. That explains why the government is after Haruka that badly.
Fuma changes subjects slightly and retells something we already know: that after the shooting of Dojima, Yumi booked it from the hospital and became an amnesiac. Fuma found her and tried to help her remember her past by showing her pictures. Although not much triggers her memory, a picture of Nishiki does. With her reaction to it, Fuma realized that it was Nishiki, not Kazuma, who killed Dojima.
During the next several years, Yumi became attached to Jingu simply because there was, as Fuma puts it, a "spiritual void" in Yumi's life that needed to be filled. Jingu wanted to be in politics for this entire life, although their relationship had nothing to do with it at first. After they had Haruka, Jingu got a marriage proposal from the Prime Minister's daughter. Yumi decided that she loved Jingu so much, she would leave him so he could take the proposal. Jingu did, and gained all his power.
Now, Sera and Jingu were always close. One night, a reporter had found out the truth of Yumi and Haruka. Jingu didn't want the truth exposed—that he had an illegitimate child—so he killed the reporter. He called up Sera to help him out, burying the reporter's body and burning all his notes and photos. However, Jingu wanted to go a step further and kill Yumi and Haruka too to completely bury his past.
Sera agreed at first, and sent a hitman out after Yumi. Fuma saved her, and the trauma of that event caused her to regain all her memory. Fuma convinced Sera that nothing could be important enough to have a woman and her baby daughter killed, so they worked together to hide them. This included altering Yumi's appearance, name, and all that, hence the forged documents.
Kazuma asks what all this has to do with the 10 billion yen Yumi stole from the Tojo Clan. Fuma replies that the money wasn't stolen from the Tojo Clan, it was stolen from Jingu's personal account.
Before anything more can be said, Terada bursts in and says that the Shimano family is outside and attacking the ship!
Use the item box and save point in Fuma's room as you need to. Haruka and Fuma will stay with Terada while you deal with the attackers.
There are fights absolutely everywhere, and Kazuma isn't sure where to start. But then, some of Shimano's men spot Kazuma, and it's on.
The first fight is pretty simple, despite being against like a dozen baddies. At this point, you should mop them up easily, weapons or no.
Shimano himself appears, and orders his men to torch the ship. They do, and Kazuma barely makes it off. He manages to get back to the dock, where Fuma, Terada, and Haruka are waiting for him safely.
The reunion doesn't last long, as Shimano and his men find them all. Words are exchanged, and Fuma summons some backup. Time for open warfare!
This battle is about 5-on-8, with the odds against you. Shimano is, naturally, the toughest of the bunch, and his minions will annoy you.
Your first goal should be to grab one of the minions and throw him into Shimano. That will knock Shimano down and make him drop his weapon. After that eliminate the minions. Your allies won't help against Shimano very much, but Shimano is a breeze if you use the shifting technique like you did against Majima.
Defeated, Shimano cries as Kazuma walks away for a happy reunion. However, Shimano spots a nearby grenade, and chucks it at Fuma and Haruka. Fuma shields Haruka at the same time Terada opens fire on Shimano. Shimano dies, and Haruka is safe, but Fuma took the majority of the grenade.
Fuma is dying, and he tells Kazuma that Yumi is at Ares and is in danger. Kazuma needs to get there and keep her safe. Fuma also drops the bombshell that he's in possession of Chairman Sera's will, and hands it over to Kazuma to keep safe. As if this weren't enough, Fuma admits that he's the one who killed Kazuma's parents to make him an orphan. Kazuma, surprisingly, takes that last bit of news in stride, simply saying that Fuma was enough a father anyway. Or at least, he tries to, but Fuma snuffs it before he can finish.