After the fight, Date returns Kazuma's cell phone. On it is a message from Shinji, saying that someone close to Kazuma is leaking information about his moves to Nishiki. Kazuma tells Date to swing by Kage's to figure it out.
Kage's got a camera in the Serena, and it's discovered that Reina has been in contact with Nishiki, or at least his people. Kazuma and company decide to pay her a visit.
Inside the Serena is a complete mess. There's blood everywhere, broken glass, turned over chairs, you name it. It's like the Bacchus, but without the corpses. At any rate, there's a note on the bar. It reads that Reina had always been in love with Nishiki, hence why she turned informant.
She converted away from Nishiki, or rather tried to, when she realized his bond with Haruka. As he reads the letter, he gets a phone call from Shinji, who reports about 10 minutes too late that Reina was the turncoat. Shinji does provide some current events however, telling us that Reina called Nishiki to the Serena and tried to shoot him. She failed, but Shinji came to her rescue, and now they're on the run.
Kazuma leaves Date and Haruka among the fresh blood and guts to try to locate his fleeing friends. But first, you can still use the hideout to exchange weapons and save. We'd recommend you do so if necessary.
Exit the Serena, then head north toward the Millennium Tower as you follow the crazy-large pools of blood. On your way, you'll be attacked by members of Nishiki's family, and they're a challenge; if you had fought them hours ago, they'd be bosses. Pretty tough, and very aggressive, but nothing you can't handle.
The first group of enemies tells you that they were heading to the theater. However, as you get to Taihei Boulevard (the street with the coin lockers), turn east. You'll hear a few people mention that they went toward the Champion District, and some more blood on the ground will verify it. You'll end up running past the drug store on this road: load up on Staminan Royals.
At the end of the street, turn north before you get to the Champion District. Basically, you'll want to turn north as if heading to Purgatory. You'll come to some more blood; turn west. You'll know you're on the track when you'll eventually come across more of Nishiki's soldiers who pick a fight. There's fewer of them than last time, but they're still awfully aggressive.
After beating them, one of the guys tells you that Shinji is in an abandoned building nearby. It lights up on your map finally, so head there. Inside, you'll get a call from Shinji, who says he's going up to the roof. The elevator is out of order, but there some stairs in the northwest corner. Take 'em up.
Enter a gauntlet! Each series of fights is pretty easy provided you keep yourself armed, and there are plenty of weapons around. Just keep heading up the sets of stairs as you win. There are multiple sets of stairs, so if you run into a dead end, back track and look for an alternate route.
Once you're on the roof, you'll have a few more minor fights. Again, in each group will usually be at least one guy with a gun. Focus on him, as bullets do the most damage. Just keep following your paths around, and when you come to a flashing red dot on your map, you'll need to hit X to jump over a railing and move on.
At the end of the massacre will be Shinji on his butt, and a guy who is his younger brother is holding a gun on him. Kazuma tries to talk him down, and basically does so. However, another guy pops up, one who is far higher in the Nishiki family. He tosses Reina's corpse for all to see, which kinda ticks off Kazuma like no man should.
The guy's name is Arase, and he's armed with twin pistols. Unlike the majority of the fights and advice you've seen thus far, you'll want to focus on the boss first. Only one of his minions is armed, making them all far less dangerous. Actually, your worst enemy here will be the camera, as it gets tough lining up Arase for combos with it constantly moving around. Try to chase down Arase to keep him on the run, and use grab moves to take him out.
Kazuma checks on Shinji, who reports that his girlfriend is watching over Fuma right now. He hands over Yumi's ring, then promptly snuffs it. Aw...