So, it probably hasn't even been a whole week, and the theory that Bunny is the one who destroyed Sae's dream have already gathered a lot of traction—it's actually a very convincing theory, especially considering a previous theory of Luna being Sae's dream destroyer.
If you have read my other theory posts, then you must have realised by now that I love overworking my pea-sized brain and overthinking shi—that's exactly what I did with this theory too, and it has made me somersault to a conclusion that their relation might not exactly be as simple as we just thought.
First thing that caught my attention was this line:
It was when Isagi said, "I'm sure you have your own things you are excited about. Everyone does!"
It's not that tough to understand the hidden annotation that he has lost passion for something he used to treasure at some point. Considering he is from a soccer manga and IS a soccer player himself, I'm pretty sure he was talking about soccer only.
Now, two possibilities come in my mind:
He was interested in soccer since his childhood, and then he lost the spark.
Something sparked his interest in soccer, and then he lost it.
For this post, I'd like to think it's the second possibility.
And if you haven't guessed it already: I think that spark was Itoshi Sae.
Sae was only about 13 when he was scouted by Re Al, meaning Bunny was about 14 at that time which places them in the same age group which further means that the chances of them playing with/against each other is quite high.
Now adding one and one together, this is the theory I want to put forward: Bunny took interest in soccer because of Sae, then they formed some kind of unusual bond and friendly rivalry, then Bunny lost his interest and basically abandoned Sae, then something happened between them just like what happened between Sae and Rin in that snowy night.
...
Yeah.
I know it sounds like some cliché fanfic, but bear with me, aight?
He does seem like someone who's straightforward with his words—he literally said, "I envy you" to a guy (Isagi) he met some minutes ago. He just seems someone.. cruel. Someone who'd leave someone just because they don't seem to give them the kind of fun they used to anymore.
And before someone says, "Sae is cruel too," let me remind you that Sae isn't cruel, he is cold. He really doesn't seem hollow like Bunny does. His emotions are present, even though his face looks indifferent most of the times which is exactly what I want to pinch right now—Sae does NOT wear his emotions on his face often, so to have his expressions twist visibly so intensely, he and Bunny must have some kind of deeper history.
And this deeper history thing is exactly where my cliché fanfic-like theory comes from: Sae and Bunny weren't rivals from the get-go.
I know that FC Barcha and Re Al are canonically rival teams, and Sae was in the Re Al from the start, but who said that Bunny was in the Barcha since the start? Who said that Bunny was never the part of Re Al at some point?
Take a closer look at Bunny's profile in Isagi's phone:
"He joined the first team midway through the season..."
Hm?
If he were to be Barcha's old member, then why would he join the first team MIDWAY through a season? Wouldn't it make more sense if he were in the the first team from the very start? I mean, he is a member from New Gen World XI!
Yes, I know that Sae is the part of New Gen World XI too but is just in some supportive team of Re Al, but you get what I'm trying to say, right?
Besides, here's the elephant in the room:
His eyes looks so dead.
Yes, his scars.
The last time we had a character with a distinctive feature in their character design, Michael Kaiser happened. Which is why I think that Bunny has to have a deeper plot/background because why else would a character of a SPORTS manga have a scar like that? The scar just seem too eye-catching to be used on a character who is just that typical talented dude who crushes people's dreams.
And why would Sae watch someone's match who just crushed his dreams? Hm?
You getting me?

















