Because Suruga insists, Rouka tells her the full story: how she met Kaiki, who told her about apparitions, and how she acquired her first piece of the devil: her left leg. It once belonged to another girl named Rouka; a high-schooler who her older boyfriend had knocked up, and whose family wanted her to abort it. With this devil’s leg, Rouka-2 almost beat her mother to death, mirroring what happened to Suruga with her arm.
The day after hugging Rouka-2 and saying she’d take the problem from her, the devil leg had replaced her crippled old one. Rouka has since replaced almost a third of her body with devil parts, and plans to “collect them all” so she can take control of the devil altogether, even though doing so will mean losing all of her body, head to toe. With that heartrendingly bleak goal announced, Rouka says farewell to Suruga, asking her to go out and “do all the human things” she can no longer do.
That night, Suruga gets a call from Karen who informs her that Rouka committed suicide three years ago, presumably from a combination of her broken leg and her “bad” family situation. Now we’ve reached nadir of Suruga’s arc: she’s been talking with a ghost all this time. Shaken and never more uncertain, Suruga simply goes out and runs. She runs and runs across landscapes until collapsing in an intersection; a crossroads (subtle!). Then a car pulls up and honks at her, and holy shit, it’s Araragi!
Like Kaiki, Araragi’s appearance couldn’t have been timed better, or be any more awesome. He now has long hair, a resplendent yellow VW New Beetle Suruga can’t help but hilariously gripe about (“What’s with this round car?”), a Shinobu keychain, and a little more life experience behind his belt. But Suruga gradually realizes once they talk that it’s the same old Araragi she’s leaned on, looked up to and missed so dearly. If anyone can help give her the guidance she needs at this point in her story, it’s him. A gorgeous, art-filmy all-night “road-trip” segment ensues.
Also like Kaiki, Araragi isn’t interested in steering Suruga in a particular direction or in doing her own legwork for her, but he’s much nicer and more caring about it. He helps her realize she’s fee to obey the opinions of Rouka, Kaiki, of her mother if she wants, but she’s just as able to fight those opinions if she’s not convinced. Rather than go along with what those voices have said or done, she decides to strike out on her own path. Araragi asks if she needs any more help, and she says no, which pleases him. Suruga’s back, and she’s going on offense.