Truly, such a beautiful way to end this arc.
I had my doubts about how a manga would handle this kind of story, considering how the medium's tendencies isn't really known for its sensitivity (pun intended). The author's afterword really smashed this perception to bits, through their love for Kaede's character that was truly felt in this chapter.
It's such a hopeful and uplifting message, that for all the horrible things that happens in your life, the door for beauty and love is never closed. Kaede's still young, he still hasn't fully experienced what the world has to offer, and for all the ugliness and pain that one adult has inflicted in his life, another adult has given him the opposite. And despite all the all the pain that Rio has experienced, she, an adult, still had the capacity to give Kaede a beautiful and shining memory. This might not fully erase the trauma in Kaede's life, but this is an important experience for him to truly process and learn about healthy feelings and relationships. And as the author says, this is one experience for him that he can fondly look back on as he grows up.
I know optimism in today's world isn't really popular, but that will never take away from the message.
You deserve better, I hope you guys are doing alright.