I’m thinking about who Ichiru/Icchan is. It could be the person who Otsuru is supposed to be, since the new baby is referred to both as “Ubuki” and “Saburo.” On the other hand, it doesn’t seem like any of the other characters (like Hatsu) are getting called interchangeably, so it might just be something they do more with a baby and not so much with an adult. So Ichiru might also be someone who’s still waiting to be reborn, who Otsuru just happens to resemble strongly. Ichiru could also be someone alive who Otsuru resembles, but I think that’s not likely based on how she’s talked about.
Chapter 1 - The senile granny calls Otsuru “Icchan” right after Otsuru firmly introduces herself by her name. Regardless of who Icchan is, Otsuru definitely has to deal with this a lot.
Then they discuss an incident with Icchan that happened when Otsuru was seven. Again, it’s unclear if “Icchan” refers to Otsuru, and it’s being used oddly interchangeably (or maybe to refer to Icchan-like behavior from Otsuru as if it’s something Icchan “did”?), or if they’re talking about two separate people. The drawing seems to depict a seven year old girl running down the hill, which lends credence to Ichiru=Otsuru, since imo if they’re different people it would make more sense for Ichiru to be older (as that would explain why the granny only sees Icchan when she looks at Otsuru. if they’re the same age then that kind of thing makes less sense.)
Then in this chapter they say “next is Ichiru-chan,” and it’s unclear if they mean “Otsuru/Ichiru will have a baby next” or “Ichiru will be reborn next.” Possibly they really want Otsuru to be the one to do it, since she resembles Icchan a lot?
(This is why I don’t think Ichiru is alive, since if she was just an alive person they’d be normally talking about her doing the ritual next, but in that case it wouldn’t make sense for her not to have been attending Hatsu’s and to seemingly be missing.)
Adding to the conundrum of what the Ichiru-Otsuru relationship is, she CAN’T just be the sister of Otsuru and Hatsu, as this chapter makes clear the already-existing implication that birth order really, really matters.
