And probably looks like an older version of one of them
And uses a clover as a theme
Notably, "yotsuba" is Japanese for "four-leaf". I think the kanji is identical, so we probably know that she's Yotsuha due to furigana.
And seems to know in advance what she's going to do, implying that they've looped at least once
And also starts while Uichi is very young, with murderous intent, again implying it's Uichi's future that's the problem, not his childhood
And is able to react to increasingly specific events the closer they are to the "happy" timeline, as though that's the version they lived through
Yotsuha can only go back in time as far as when she put the clover in the watch. In a sense her significant moment with the clover was putting it in the watch.
Uichi picked the clover when he was younger. His significant moment with the clover was giving it to Yotsuha.
There's foreshadowing that Yotsuha is going to die due to trying to save Uichi
Kinda weird that our villain doesn't just shank Uichi, tbh. Not worked out if or whether that fits in, or if it's gonna get handwaved. We never see the villain. Is there a reason they have to act through intermediaries?
So either:
Uichi gets a one-shot trip back after receiving the clover from her on her deathbed, and wants to prevent her death. He doesn't mind how much he suffers to achieve this. On the other hand, time travel in this universe has been rewind-based so far so can we even have two Uichis at once? Or was his wish different?
Big bro gets a one-shot trip back and wants revenge.
It's her father. The magic of wishing on a clover runs in the family and he named her that way due to the strong family connection to the plant, and he wants to protect her.
That, but as a cosmic force: someone (maybe Uichi for the extra pathos) wished on a clover that she'd have a long and happy life, and perhaps going through this and accepting his death is the only pathway for that to happen for her.
Regardless of Clover's identity I bet that the mom is still alive. Solely because I have a hard time believing that an author would create a striking character like that only to unceremoniously kill her offscreen, and manga/anime rules say that if a corpse is not shown then the character is still alive.
I see a lot of people speculating on the incest route on the last page where someone who I assume is clover because of the similar hairstyle to that one dude Uichi saved from bullying in middle school (i forgot which chapter but clover’s face was shown), says they really do look alike. But I’m almost certain that who Clover is referring to is Rikka and Yotsuha being siblings and not Uichi and Yotsuha. It makes more sense to be this because he says this after putting the letter in Rikka’s locker. Also I feel like its foreshadowed that Rikka and Yotsuha are somehow related because Rikka’s name in the Japanese version is 六花 or 6 flowers and Yotsuha’s is obviously 4 leaves.
Probably referring to the father reveal later and how yotsuba looks like him.
But man, Author, My dude, Light of my life, producer of everything that gives my life purpose, Bestie.
He is talking about someone HE knows and saying they really are related. So, the step bro (or dead psycho mom) since he really does look like her. He probably doesn't know the "step" part though.