I think the thing we are not realizing with SaenAi is that Ai probably wanted to go to Japan because he wanted to find a place where he felt like he belonged, a place where he could feel home and be himself. These are all conclusions based on that one time Ai mentioned his family and said they were very strict. A lot of different kind of trauma can be caused from a household like that but I think the biggest consequence this type of trauma can have is wanting to escape, as fas as possible. So I'm assuming that Ai just probably wanted to realize his dream somewhere far away.
But then he meets Saen and as that song goes "I never knew what love was until you loved me" and similarly, he never knew what home was until he met Saen and he found a place where he could feel like he belonged.
And that dialogue in ep 9 right before they kiss is so important actually because Ai openly asks him why Saen doesn't boss him around (and Ai is probably very aware what being bossed around feels like) and Saen, this sweetheart, tells him that he doesn't feel the need to because he is always satisfied when he is with Ai. And that means so much to Ai, because there is a person that finds him loveable as he is, with no need to change and adjust and fix himself and his habits for. And then he does melt, a little hesitantly but he still does as he says "Saen, you can".
And now Ai feels loved with Saen, he has found his home, place where he feels like he belongs. So he doesn't need to escape far away anymore, as far as he is rn is enough because now he has something to hold onto, someone to protect and sometone to protect him in his life and he is satisfied even here.
In conclusion to this essay, I just believe that Ai is a traumatized baby and it's showing. Also You're my sky is all about the feels so yes. Thank you for coming to my Ted talk.
