@Lex79
Sorry for the long wait, Lex79. Here are my thoughts on who Rena is.
With all the mystery surrounding Rena I have been searching for my own theories and possibility as well. Here is what I come up with. Do note that it’s all speculative and I could be very wrong on who it was.
Before we start guessing who, Rena is. We must first ask the question of why Rena appear in the first place. I believe there are three reason all together including two condition. One reason is because she knows of the harsh things Nino said to Fuutarou when he first visited Nino’s suite, the other is when he talked about his reason for studying to Itsuki, and the last is to either cheer the him up or encourage him at his job.
Now onto condition. She must know where or at least the general location of where Fuutarou will be at during that time of day and must have the free time to find and meet him, even having a boat ride for an X amount of time as well.
With those five things in mind the one that fit all the requirement the most for me is Miku. Let me explain, Nino is out because of the difference in fingernail lengths between hers and Rena, as well as there’s no indication that she even knows where Fuutarou will be at that time beside being at school and at the entrance of the hotel.
I also cast Yotsuba out due to her having her hands full with both studying and helping the Track & Field club and given how surprise she was when she come across him by the lake, and the fact that one of the T&F members had been accompanying her during that day, it doubtful that she have the time to be Rena. So that leaves us with Ichika, Miku and Itsuki.
Itsuki is a very likely candidate but because of what happens during the school trip, she won’t be disguising anytime soon, at least not by her own volition and even if she did, there’s no place where she could have hidden the disguise set afterwards because she was staying over at the Uesugi, and with how rundown the Uesugi home is, it would surely stick out like a sore thumb. Also, she doesn’t know about the thing Nino said to Fuutarou at the hotel which is one of the big reasons why I think Rena appear. In Ch. 45, she does notice his depression and strange behaviour but seem oblivious to event that transpire. Other than that Itsuki’s mind is mainly preoccupied by Nino, studying and being a good house guest.
Finally, Ichika and Miku. They are the two strongest candidates to be Rena. They’re both are good at disguises and have a place where they can hide the disguise afterwards (their home). Though circumstances tend to favour Miku in this case as Miku has the most free time available among the sisters compare to Ichika who has the second most time constrain among the quint. Miku was with Fuutarou for the majority of that Sunday whereas Ichika has work during that Sunday. And other than Sunday we don’t know for sure whether Ichika has work or not with the subsequent day leading up to and during the appearance of Rena, while Miku do have the time necessary to plan this out. Miku also there to witness Nino lash out at Fuutarou when they first find her at the hotel (surprisingly she didn’t engage Nino because of this) this may give her an ideal of what could be the likely cause of his depression.
Nonetheless there are two major problems. The conversation Itsuki had with Fuutarou that night, as well as Fuutarou whereabouts during the day “Rena” appear. But there is a way on how it’s possible for her to know both that conversation and the general whereabout of Fuutarou for that day. Here’s how with my speculative timeline.
-2 Dec, Sun-
[Fuutarou is at home but Itsuki hasn’t arrive at the Uesugi house yet. Over at the quints house Ichika have actress work to do while Yotsuba has to help out with the Track & Field club, leaving Miku alone in the house.
She then contacts Fuutarou to come over, so she could explain the current situation and to go look for the two runaways together. It should be around this time that Itsuki reach Fuutarou’s home and ask if she could stay over.
Fuutarou and Miku manage to find out where Nino is staying. Fuutarou tried to convince her to return home but she lashes out at him, took his bracelet charm and threaten to call security. Fuutarou and Miku retreat. Around this time Itsuki was probably at or close to the area of the lake mulling about how she was going to get her things from home when she encounters Yotsuba with the T&F members on their training route and have Yotsuba bring her bag.
Due to a lack of hint of where Itsuki disappear to, Fuutarou decide to end today search. Miku inform him that Itsuki didn't bring her wallet. They part and Fuutarou went home. Upon reaching home he discovers that Itsuki is staying over. At some point Miku meet Yotsuba either at home or somewhere outside, who told her that she had deliver Itsuki’s bag earlier before at the lake. With this new hint Miku goes back out there to search for Itsuki.
Fuutarou and Itsuki went for a walk at the lake. Miku finds them but for whatever reasons, hid herself. Fuutarou reveal why he study to Itsuki. He then senses a presence nearby but dismiss it as nothing. Fuutarou and Itsuki return home. Miku having eavesdrop on the conversation, decide to leave Itsuki in his care and return home.]
That is what I believe happens on that day. It just so happens that one section of their training route use by the T&F members is close to where the Uesugi live, that’s why Yotsuba is surprised to come across Fuutarou there. Do keep in mind that the latter part of this speculative timeline after Miku and Fuutarou part could also be applied to Ichika as well if time is by her side. So why am I leaning more towards Miku? Because in first page of Ch. 45, Ichika inquire about the whereabout for their sister, showing her concern for the situation, while Miku seem certain that they will return home soon. What warrant her to believe that other than seeing Nino leave her hotel is… questionable, given what’s been happening beforehand it is definitely suspicious, especially with how different it is compared to her concern in Ch. 40.
Then we have the charm Rena toss to him as well. “Rena” said to Fuutarou that if he ever acknowledges himself, he should open it. Regardless of the content inside, there is anticipation from “Rena” for Fuutarou to open it, but as of now (Ch.68) there is no sign, thought, mention or indication about it from any of the sisters after the “Seven Goodbye arc”, so we can either assume that she believe Fuutarou had already opened it or she knows of Fuutarou losing her charm. I guess the latter, because it was supposed to help him somehow, so when news of his resignation was revealed, it's easy to conclude that Fuutarou still hasn’t acknowledge himself and thus did not open it.
The only one that I could see that is close enough to him when that happens is Miku. With one panel supporting that claim with Fuutarou, Miku and the charm altogether. Remember, this is during the night, and they're in the frigid water, the charm is small, and Nino is in danger in the very next moment, so there’s a very small window of possibility for anybody else to notice it being swept away.
If Miku is Rena, the next question would be. Why didn't she reveal her real name? One guess for me is that she is ashamed of herself having not achieve her ideal self or anything at all, a failure with nothing to show for, compared to Fuutarou who manage to become top of his grade and is now a tutor teaching them. She probably don’t want to ruin the image of his belief with her failure, that’s why when Fuutarou asked if any of the sister have met him before in the past there is no answer but while the other three look straight at his direction, the only one who’s not looking directly at him is Miku and in that panel she is also a step back compare to the others like she’s hiding behind her sisters.
Then the biggest question for me. How does she come to the conclusion that Rena needs to disappear? She comes to meet Fuutarou specifically disguise as “Rena” because if anyone can cheer him up at his lowest it’s the girl of his past, but she quickly concluded that leaving him is the best course of action. It confused me when I first read it at how fast she conclude that. So, I been racking my mind for a possible answer and I think I found one. They’re both bound by the past. Just like the reason I gave for why Miku hides and conceal her identity above. Despite all the accomplishment Rena listed the only thing Fuutarou will ever consider is becoming necessary to someone, otherwise he deem himself to be a failure.
That’s when I believe she realise why he had tried to run away earlier, because she is in the same boat as him. Except in Fuutarou case it’s quickly becoming a double-edge sword for him. She then conclude that it’s more important to rid him of his past expectation and have him develop confidence in the current him. That’s why she took the photo, told him they’re never seeing each other again and later toss him her charm with that very specific condition to open it.
There, those are my theories and speculation, with Miku having the most circumstantial evidence to be Rena, followed by Ichika if time is by her side. What do you think? Is there any point you disagree with? If so why. Are there any other possibility or evidence that I might have overlook for the other quints? If so, I would love to hear it.
