Author's Note: I am going to alternate chapters for this fic. One chapter of developmental differences, one chapter of life differences, and then I will alternate from one to the other. So read this, and then keep in mind that next chapter you're going to see me fictionalize what I just laid out.
Don't say I never tried anything experimental and different.
Cho Development 1
Differences.
In one world, a boy forms in a void of darkness - one X, one Y.
And in another world, the slightest shifting of cells happens - one X, one X.
A girl forms in a void of darkness.
This changes everything, you see.
Her parents are Shiba Isshin and Kurosaki Masaki. She is their first child, due on July 15th. They decide to name her Cho - butterfly.
So here is the first distinction. In one world, the parents are expecting a boy named Ichigo. And in another, they are expecting a girl named Cho.
In one world, Ichigo grows more quickly during gestation. He becomes larger, heavier, physically sturdier, with a thicker skull and a bigger brain. He becomes, in other words, a boy.
In another world, Cho's body matures faster - no matter how much smaller and more delicate she is.
She is better able to handle challenges outside the womb by birth, and is less vulnerable to various illnesses, cognitive and behavioral problems, and even death during the early prenatal and postnatal period. Her mouth even moves more often in the womb, an important precursor to suckling and swallowing harder.
Cho responds sooner to external stimuli outside her mother's tummy than Ichigo does - kicking, punching, twisting, and turning in response. She also habituates, or ceases responding, to external stimuli earlier.
For all his greater size and strength, Ichigo is actually more vulnerable at birth - more likely, for example, to develop developmental issues.
Cho is delivered by her own father, a doctor in a fake human body, in their own little private family hospital with the sounds of modern city Tokyo just outside. She is born into daylight. Her first hours are warm and filled with love and her birth parents' smiling faces.
As the next days and months pass, she gets used to the faces of Isshin and Masaki and she is their sole focus. Masaki is already planning for her eldest daughter to learn archery, karate, and kendo.
Her parents also notice that from her earliest days, Cho waves and coos at ghosts who pass through her room. Isshin and Masaki make the private decision to raise her without letting her know who she is, though they also intend to raise her as if seeing ghosts is normal - their own little private family secret.
As she grows into a toddler, Cho is already raised realizing both that she can see the dead and that nobody outside her own family will believe this about her.
Cho was smaller and easier to deliver than Ichigo, and she was tougher in the face of the new world, better to fight off things like infections. She is also less fussy as a newborn than Ichigo, her nervous system having matured faster - this will become important very soon.
Cho is more likely to openly express pain as an infant, she has a keener sense of smell, her hearing is keener but she is worse at pinpointing and localizing sounds than Ichigo, and her vision is worse than Ichigo's. There is no difference between their motor skills. However, Cho's motor skills are encouraged less than Ichigo's are - the first of many social lessons asking for Cho to be less physical than Ichigo.
Cho is more social at an earlier age than Ichigo - she speaks more words before him, and begins waving, gesturing, and pointing more with her hands earlier than he does. She begins stringing sentences together earlier. And though as a toddler Ichigo is more likely to pretend he is reading, driving a car, or pounding a hammer - Cho is more likely to imitate gestures such as hugging or rocking a doll.
Ichigo, because he is a fussier and more difficult baby, having matured less quickly - here is where this becomes important - has internalized more by the time he is a toddler, has internalized lessons from his parents that he has to control his emotions. So by toddler age he is less emotionally expressive than Cho, who was a pleasanter baby and thus is more open with the emotions she is experiencing. She is more likely to do things like make eye contact and express open interest. She is even more openly empathetic to others' emotions than Ichigo is, relating to others more instinctively. She is also trained to be more empathetic and social, and to have more charming social interactions with others, to be seen as a more charming baby.
Cho is held more than Ichigo. She is considered prettier, softer, more delicate, weaker, and finer featured. Anger and distress are discouraged in her, while joy and interest are encouraged. Her physicality is not nearly as emphasized. This is particularly pronounced in her father figure Isshin, who treats a first daughter wildly differently than he would a first son. Where Ichigo is trained socially early on to be a man, Cho is from an early age the "darling" and "precious" baby girl daughter.
Meanwhile, anger and stoicism is encouraged in Ichigo, who is pushed more in the direction of physical motor skills and sports and is not held as often. Ichigo is treated more physically and bluntly, and is less required to be empathetic and read subtle nuances. Cho, meanwhile, is trained largely verbally and in subtle social nuances.
While Ichigo gets balls and hammers as toys, Cho gets dolls and hairbrushes. Her room is pink instead of blue and while Ichigo is more likely to get older-kid baby gifts, Cho is more likely to get age-appropriate things like rattles and mobiles. And while both prefer their mother as caregiver, Cho begins to emulate her mother Masaki in emotional expression, visual attention, and physical mannerisms in a way Ichigo does not.
And so Cho becomes loving, compassionate, protective - and also extremely busy and selfless, always mothering and doing everything for everyone. She also inherits from Masaki a strong confidence and a somewhat sarcastic sense of humor, a strong personality that tries to seem cheerful even when it is not. Cho from a young age becomes the smiling and cheerful but bossy mother figure.
Cho's earliest years are in a wealthy suburban home in modern city Tokyo. She is the only child of two adoring parents. This also shapes the kind of smiling, loving, but very busy, bossy, and confident, no-nonsense caring person she becomes as she grows into a toddler.
By the time she is a toddler, Cho has a short head of chin length orange hair, almond shaped amber brown eyes, high cheekbones, a heart shaped face, and pale golden skin. Masaki dresses her, so she ends up in checkered and sailor type summer dresses, cute little animal accessories, country looks like tiny boots, cute little blouse and wool skirt sets, gauzy innocent dresses, country shirts with gauzy skirts, soft old-fashioned embroidery, necklaces and soft velvets, and wool button-up coats. She is almost a tiny, sophisticated Mori girl, with a short head of orange hair.
And so just as Isshin gives her more training in what it means being a daughter instead of a son, protective of her as his "little girl," it is Masaki who gives Cho her first lessons in what it means to be a woman.
This is the beginning.