18 years old

The sister nudged the other in the shoulder in class during lunch break and giggled, "C'mon now, Naomi, your practically drooling over him."
Naomi, the sister, jumped and quickly looked over at her twin as her face turned dark red,
"Gosh, Kazue, don't scare me like that!"
Kazue laughed loudly, "Better get in line, almost everyone in the whole school likes him." She warned her sister as she gestured over to the classmate they were talking about.

Isamu Kamei, probably the flirt of the school but definetly gets who he wants.

And speak of the devil, he felt the girls gaze and looked over at her and gave a goofy grin. This set Naomi's heart ablaze as it obviously showed on her face. Isamu noticed her blush and waved to the group of girls he was talking to, much to the girls dismay and jealousy, Naomi with the same goofy grin. Kazue wished she had popcorn because she loved every minute of this.

"I noticed you were staring at me, may I ask why? I don't mind it of course since it's coming from a pretty lady as your self." He winked at the timid girl.
Naomi averted her eyes a bit and looked over at Isamu again, "I-I um...well..."
The girls twin totally butted in, "She totally likes you dude-"
The other girl tensed up and blushed a darker red if possible, "K-Kazue...!"

Isamu himself looked surprise before returning to the way he was before, "How wonderful to hear, dear old kindergarten crush." He chuckled as he had his own blush on his face.

This was the start of their love.

Though the couple had no idea of the crush her sister Kazue had also developed on Isamu.

22 years old

Now Naomi and Isamu lived together and we're married, already expecting a child. Sure they were going quick into family but Isamu said he couldn't wait. Though...their occupations. Isamu stayed home and had little side jobs he had to do if he had to.
Naomi on the other hand was a complete surprise on how she turned out, yet still the same timid girl.
Naomi was a stripper. Surprising yes, but she literally tried everywhere but this was the only place that would except her offers...for obvious reasons.

Nonetheless, Isamu still loved his wife and supported her in anyway.

If only it could've been that way forever.

23 years old

Naomi started puking in the toilet in the middle of the night. She felt like she was puking her brains out, she felt like dying. By this time, they have already had their first child which they named Kasumi. And speaking of little Kasumi, she heard her mother puking her brains out and slowly opened the bathroom door and saw her mother leaning her head on the toilet. Kasumi quickly rushed to her mother's side and rubbed her back, "Mommy..Mommy..?" She asked, genuinely worried since she had no clue what was going on. Naomi smiled weakly and placed her hand on her small daughters, "I'm fine dear...I'm fine..."

Isamu eventually noticed both his wife and his daughter was out of bed and noticed the noise coming from the bathroom and opened the door to see the two of them. He too also rushed to her side, "Honey, are you ok?" Concern was written all over his face. Naomi on the other hand seemed scared and hid something in her hand, "I-im fine dear..."
However, Isamu had noticed that she was hiding something and quickly took it from her. His eyes widened and looked at Naomi sadly, "...Naomi..we haven't done anything like this together ever since we had Kasumi. What is this?" He said as he opened his hand and reviled a positive pregnancy test.

Poor Kasumi was confused and kept her hand on her mother's back, now grabbing onto her sleeve, "Mommy..?"
Now after hearing her daughters shaking response, the tears spilt down her face, "I-im so sorry....I'm sorry Isamu, I'm sorry Kas..." she sniffed and chocked on tears, now sobbing. Isamu looked down in his wife in shock after he realized what had happened and then acted in rage, grabbing Kasumi and standing up, "..Leave.." He said coldly, now blind by rage.

Naomi's eyes widened and shook her head, she couldn't believe what was happening and stood up, "..W..What..?"
Her husband grabbed her arm with his free arm, "...I stayed loyal to you, and yet you couldn't do the same to me- Leave." He said and then guided to the door as she protested and pleaded.
Kasumi started to cry, "Mommy..? Daddy..?"
Isamu then looked down at Kasumi and gave a warm smile, "It's ok honey, it's just you and daddy now.." He said in a way to comfort her since he said it in a soft voice and she was still a baby so she bought it.
Naomi now stood outside of the door, millions of more tears spilling down her face, "Isamu...please...I'm sorry..-" she was cut off with the door in her face.

It was now just Isamu and Kasumi.

25 years old

After the incident, Isamu drank all of his problems. He regretted every decision he had made and usually cried when he drank but would eventually turn into a angry drunk. Kasumi slept a lot and despite only being 2 years old, drew a lot. And since her dark blue hair, which she inherited from her mother, Isamu would put them into twin braids every morning. They lived pretty good with only the two of them but now he had to have a actual job so he was mostly looking for jobs a lot of the time.

He still misses and regrets doing what he did to Naomi. Isamu never remarried.

Naomi on the other hand, already remarried to the man who's the babies was. His name was Edward and he was French. Now, on how they met was pretty weird. They met at Naomi's work but he would only request her. But instead of doing the usual lap dance behind closed doors, he liked to know more about her and vice versa. Eventually, they became very close and they both developed feelings for each other and eventually had sex behind said closed doors after a few months of knowing each other.

The two of them live happily and their child already born. The child's name was Kazumi Roy. Naomi wanted her name to be similar to Kasumi's since she never saw her again. That and she thought the name would suit her baby, which Edward also agreed on.
The new couple lives happily together with no problems with their daughter. Edward enjoyed teaching Kazumi French which she is now fluent in.

---

Kasumi huffed, now in present time, telling someone about her parents, a small smile appearing on her face, "Heh...I haven't seen my mother's face at all...if I did, I don't remember it." She paused and her face turned sour, "My father's a asshole.."

Kazumi tilted her head, also talking about her parents to someone, "I love my parents. My mother is very kind to me, so if Aunt Kazue, and my father teached me everything." 

---

Also I thought of a headcanon for Kazumi.

So their mother had pretty big breasts and so I realized Kasumi obviously didn't get it so...what if Kazumi was the one to get those genes- part of the reason she wears a binder is because she likes dressing more masculine and because her boobs are big like her mother's-

I wanted to add this just to make you feel better about the feels-