Who do you think is the bride? (Spoilers)

Only_Brad said:
Itsuki of course. First girl always wins.

PulseZer0 said:
Itsuki.

There's really more to her if we pay close attention to the details. No, really, all of them make good plausible candidates, but my answer lies as objectively as possible from the perspective of pure chemistry and compatibility, notwithstanding the future arcs/progression and speculation.
(Some spoilers below of course...)

I'd just like to point out more of the subtle or at least not as obvious events/actions and implications instead of the major plot points that most if not all of us would already know:

- Itsuki and Fuutarou were able to overcome their grievances towards one another pretty early on and going on to develop the most relatively healthy/natural interactions and relationship
- Present Rena being able to cheer Fuutarou up; knowing how to push the right buttons. All the while she is able to manage her emotions and feelings well as to not build too much of a tension/barrier between her and Fuutarou or her sisters (she does this the best)
- Itsuki the first holding his hands at the campfire, small point, but a possible big hint nonetheless.
- On Fuutarou's birthday, Itsuki's energy drink "gift" was the first to be accepted by Fuutarou without any hesitation. She one-upped her sisters as if it was nothing, dang!
- Itsuki getting along well with Fuutarou's family, even staying over at his place. Think about it, Itsuki could actually pull this off as if it was almost natural.
- Itsuki is actually quite determined, studious and diligent; she aspires to be a teacher and to be like her mother. Not a vital point but good to consider nonetheless

The significance of these events/actions shows that:
1) Itsuki knows Fuutarou well and becomes his reliable pillar of support when he needs it the most. She's there when he needs her and vice versa, almost unwittingly.
2) Both are most comfortable and quite open with each other with relatively little tension/barriers between them. The other sisters all have something in the way of being able to actually reach out to Fuu or the other way round.
3) Their compatibility in character traits. At certain times, they are also shown to express unconditional concern towards one another without the other (or the readers) even realizing it. Let's face it, the other sisters all really have their own self desires/motivations, not saying it's bad/a deal-breaker or anything, but Itsuki has had her many important moments behind the scenes and she's perfectly fine about it.
4) Itsuki is wiser than she lets on, at least when it matters the most. She has been playing pivotal roles in many of the major plot points across the entire source material we have so far even though she may not have the most dedicated "screen-time" as of yet.
5) She is always the first or the winner of whatever "love destiny" events, and somehow she does it with the least effort like as if she's naturally the one.

Well of course it's all still up for contention, and that's the draw of this specific series. While Itsuki gets my vote for Fuu's bride, I personally would pick Nino for myself (just don't drug me pls) :D