I honestly like the plot with Yuhi being the reason Suzumi decides to keep living. I like that he has people who care for him, and that his brother wanted to look after him, while his father also wanted to care for him, even if there isn't much evidence the man did anything other than acknowledge him as a son. This plot deals with the complexities of adultery and how children suffer under the weight of terrible adult decisions, which contrasts with the idea Ceres states, that children are happy events (well in the anime I think the official subs call it the happiest time, but the manga just leaves it more open: that she was happily married and expecting a baby with her partner, which was the happiest time of her life). Yuhi's presence, meanwhile, was so unwelcome in a way that his mother eventually left him behind, possibly out of pressure from Yuhi's father or Yuhi's father's wife. We just don't know, which makes it odd for why Aya states that she didn't abandon Yuhi. For all anyone in the know knows, she did.
What's less compelling is how Yuhi assaulting Aya when he states his love is handled, and how no one notes that his behavior is an issue, at least in a way that makes sense. Mrs. Q seems to take it that Aya and Yuhi are a couple, Suzumi - even after being assaulted by a group of men - also takes it as love, and while Ceres calls it assault, repeatedly, and pushes back that love doesn't excuse everything, she relents, too. It's not like the fictional narrative has to say assault is wrong, but this might be playing with the idea that even victims who knows a terrible thing happened struggle to vocalize it. As a result, Yuhi's behavior doesn't change. He's apologetic for some vague part of his actions, but believes his intentions are good. Aya, meanwhile, wrapped up in a dozen forms of trauma, is at turns ready to beat him up for touching her and also notes that she's sort into it on a physical and perhaps emotional level. But she's also a teenager - they both are - and it's possible they're just confusing lust for affection (especially with literally no adults around willing to help them; I love Mrs. Q, but she's very unhelpful in this avenue). Aya knows something is wrong, and struggles to vocalize it.
Also I don't know if I missed it somewhere, but where did Yuhi learn martial arts? I know he's into cooking and music, and his interest in school is dubious, but where did he learn to fight exactly? This is never explained and it was while watching him take out the Mikagi thugs in the anime adaptation of the first arc that I realized that has yet to be explained, even in an arc heavily involving his backstory.
The hospital arc is boring. Like I could go on about how it's kind of piggybacking on the narrative theme of suicide presented in the previous arc, and how important it is to give living a shot, or something about how the arc plays with Yuhi and Toya's relationship (at first hostile and then humorous when Yuhi grabs Toya in order to ask where the bathroom is, and then a bit tender and/or jealous when Yuhi ignores Toya in favor of trying to save Shota), or that Aya is realizing that her messing with Toya could hurt Toya and isn't as clearcut as she tries to think in her affection... But most of that isn't compelling to read. I'm not interested in Shota or Chidori or the new C-Genomes. It's a set-up for later material.
I appreciate Aya really coming into her own and taking a hand in her own destiny in this arc, at least. She's heavily traumatized and deserves a break from all the horror, but she's stepping up and trying to take control of things. For a 16-year-old who's gone through as much as she has, that's saying something.
Meanwhile, Aki is being subsumed more by his ancestor's personality, which is troubling him more and more. His fear of who he's turning into, and his increasing inability to trust himself, spurred on by Kagami just wanting to screw around, is quite tragic. I like the development of characters around Aki, as well. Although he's not the protagonist, he's arguably the deuteragonist, and he's surrounded by a cast of interesting people (namely Alec and Toya) with their own stories and relationships to him.
All in all, it's a plotty volume that presents a few interesting things, but I can't say I recommend it to anyone.