Theory About The “A Fallen Apple” Title
Keeping in mind past references in the manga and the biblical sense of the apple as a forbidden fruit of wisdom and knowledge.
1) Act 73: When Kuon pretends Kyoko is Mizuki he calls himself ‘the biggest sinner in this whole world’ for wanting to be with her.
2) Act 99: Reino calls Kyoko ‘an apple.’
So, after having Kuon call himself ‘the biggest sinner,’ Nakamura introduces ‘the apple’ as an euphemism for Kyoko. Then, in a biblical sense, for Kuon, Kyoko is like a forbidden fruit for more reasons than the mere age difference.
3) Act 115, 119, 120, 122: Kuon carefully chooses Kyoko’s birthday gift and how to give it to her, an as-subtly-as-he-could-put-it declaration of love.
Act 139: When Kyoko asks him if she can give him his birthday present in St. Valentine’s day, he can’t help himself but to hope she took the hint and will return his feelings.
Act 148: When Kyoko’s VD gift happens to be especially made for him and presented in a glass that reminds her of Queen Rosa, he feels for a moment that she has returned his feelings.
Act 150: When he has to take his kiss back for her sake, he refers to that moment as ‘the moment I was allowed to touch her:’ Kyoko is forbidden to him (the biblical apple, a forbidden fruit out of his reach) but from all the obstacles between them, the one he talks about here is not knowing her true feelings. She’s out of his reach as long as he doesn’t know her true feelings. So if he finds out she returns his feelings he would pursue her regardless. Also stated in Act 94 when he says he would even go against fate and God to break whatever bond she still has with Sho.
4) Act 190: With the grip on his emotions stretched to the limit he says ‘but I intend to keep doing it…’ in response to Yashiro talking about how vulnerable Kyoko is.
5) Act 192 to 195: When Kuon gives in to his dark emotions and unleashes himself on Kyoko, she stops him and forgives his transgression with an innocent kiss, a moment marked with crosses all over it. The cover of chapter 195 is a crucified woman with a serpent wrapped around her, more biblical stuff: the forbidden fruit, the biggest sinner, her forgiveness, his redemption and salvation by her hand.
6) Act 207 to 210: When Corn and Kyoko are reunited, they share about their difficult pasts and Kyoko tells hims what she has learned from her experiences.
Kyoko keeps mentioning Ren Tsuruga. This upsets Kuon; “why she keeps mentioning my role when I’m with her?” Still unable to tell what her real feelings are, he asks for a kiss on the lips hoping to get some clarity on that (the fruit of knowledge, reaching out to her.) Instead, he gets a kiss even more innocent that the one he got last time. But it’s still enough to focus his thoughts. Relating to Kyoko’s point of view on her past, Kuon is able to see his own experiences in a new light (the fruit of wisdom.)
7) Act 276: Boh calls his love a forbidden one. (The forbidden fruit again.)
8) Act: 280: Kyoko nods in response when he asks her if she feels the same as him. (The apple falls within his reach.)
Now that ‘the apple has fallen’ and they are out of the elevator, Noah’s ark, the ‘Sneaking onto Noah’s Ark’ arch ends.
9) Act 281: So the next chapter is called ‘A Fallen Apple’ where ‘the biggest sinner,’ with ‘the apple’ now within his reach (the knowledge that Kyoko loves him too,) for the first time states out loud his desire to have her: “I’d like to have the right to call myself you ‘boyfriend’…”