The one prior change is a change to Tsukimogumogugami whatever she's called's role. Here she now revives Aqua and Ruby specifically to put them in a position of "power" and offer them a wish, because in this setting gods exist to make sure history keeps being made or some shit. You could make it some statement about celebrities being the royalty of the modern era or whatever.
Anyway, either Ruby's already used her wish, or there's only one wish between them and they've agreed to let Aqua use it, whatever. The slander-movie is almost finished, getting ready to be released. Aqua has been biding his time, doing as much as he can with his own hands to save the wish for the most pivotal moment, and is now planning to use it to make sure the movie has the most impact possible. But what's this? The man they hated without any understanding is slowly turning out to be a victim of his own tragedies and not like what they made up in their minds at all. Aqua keeps making excuses to himself to justify his continued hate- oh he didn't literally send a stalker to kill mom but he's indirectly responsible!- but even his will is breaking.
Finally just days before the movie wraps, Aqua ends up meeting with his father on a cliff overlooking the beach and like hypes himself up convincing himself he was right, this guy just has to be evil, bringing a knife to kill he man right there and then if he can... and he finds a man terrified of being rejected but clearly overwhelmed with happiness to finally meet his and Ai's child. The grown man (yet way younger than he should be) before him trembling yet hopeful blows away any last delusion Aqua was clinging to, and he asks himself... what the fuck am I doing? I'm about to ruin this man's life for like the third time, all because of the hateful image I've clung to! No matter what he does now the movie will still be moving forward and turning this man into a pariah in the eyes of the public. Overwhelmed with guilt, Aqua turns the knife on himself and plunges over the edge. (You can make this the cliffhanger of a chapter and make it look at first like he attacked Hikaru and there was a struggle, but actually Hikaru tried to stop him.)
Hikaru barely manages to drag Aqua to the shore, but collapses. Tsukumogomogugami appears, looking down on Aqua who barely clings to consciousness. Your life is fading, she says, so it would be waste if you didn't use it now- what do you wish for? Aqua looks at his drowned father beside him, coughs up blood and seawater, then chokes out- please save my father. Tsuku smirks- as you wish. As Hikaru stirs back to life, Aqua's vision fades to darkness...
The news erupts. Hikaru is Aqua and Ruby's real father! There was a struggle to the death on the cliffside! All sorts of rumors abound, with many connecting them to the upcoming movie about Ai, believing that Hikaru father bad is what the movie was trying to tell them, therefore it must be true. The main cast reels in shock- Aqua stabbed Hikaru? Hikaru stabbed Aqua?? Is Aqua dead?? Panic is erupting, and then-
Aqua wakes up in the hospital. Because what really happened after he blacked out, and how the father information really got out, was thus- Hikaru carried him to town and cried out, please save my son! hory shit. Hikaru is probably sleeping in a chair in Aqua's hospital room, watching over him. Despite everything the man just wants a chance to care for his children.
Aqua realizes what a cunt he's been. His "accident", however it ends up perceived by the public (possibly correctly, as a suicide attempt that his father stopped, minus the part where he tried to kill Hikaru at first, possibly plus some assumption about the sort of mental stress he was under as a child star) gives him an excuse to pull the plug on the slander movie at the last moment, leaving it shelved. The public might be able to put together the general truth, that is was a smear campaign aimed at someone who turned out to be innocent, but they'll never know for sure. Or they believe it was an attempt by the twins to contact their father and it was pulled because they managed to, you know, contact him.
Everyone moves on. Aqua might retreat from the public eye, could even use the hospital thing to pivot to medicine again like oh these people who saved my life really inspired me. At any rate, the Hikaru family, such as it is, half brother included, is now together and ready to start healing. Tsukumogumogugami looks down upon them taking the first trembling steps towards a happier life and makes some remark about the smaller changes in people's lives being just as impactful as the major ones, then turns into a crow and fucks off. The four family members pile into a car and go on a road trip (half brother is not allowed to drive because he crashed the car that one time). An open-ended, maybe some what bittersweet with a leaning towards sweet ending.