Y/N = Your Name
* 3rd Person's P.O.V
It was breakfast, The Sakamaki brothers were at the table. Reiji brought his adopted sister Y/N into the room, He placed Y/N on a high chair. Ayato was eating some Takoyaki. Reiji gave Y/N some apple slices. She grabs an apple slice and starts eating. Laito was chewing on some Macaron. " What a surprise to have a human as a sibling," he said." Does that mean she's food to us?" Laito added. " For once, maybe Laito is right. What if she is food?" Shu said." Y/N's not food. She's our adopted baby sister" Reiji said." Father's words against yours. Now shut up and eat your garbage" he took a bite of his Spaghetti Carbonara. Subaru was just minding his own business." Not even just one bite? I bet she'll taste delicious" Kanato turns his head to his adopted baby sister. " Teddy thinks we should try" he held his teddy bear close." I said no!" Reiji slams his hand against the table. Everyone just stared at him, " Just eat" Reiji sighed. All the brothers look at each other before eating.
* Time Skip
In the living room, Reiji was changing Baby Y/N's diaper. " When will those boys learn?" He pushes his glasses up. Baby Y/N was giggling at him, she grabs his glasses. " Y/N give those back," Reiji said. He tries to snatch his glasses back but, Y/N was swinging them around. Reiji grabs the glasses and pulls them away. " Never steal from Reiji" he places them back on his face. His sister started sniffling. " You're not gonna cry are you?" Reiji asked. Baby Y/N started crying, " Oh come on" Reiji moaned. He walks to the shelves and grabs a backpack. It was filled with diapers, toys, and food for Y/N. Reiji pulls out a baby rattle. He shakes the rattle in front of his baby sister. Y/N grabs the baby rattle and starts giggling. " You're so stubborn" Reiji sighed." You have a lot of lessons to learn" he picks up his sister. Y/N hugs Reiji, Reiji flinched and hugs back. He sighed as he patted her back.
The Sakamaki brothers were outside, Kanato was crying. Laito and Ayato ran over to him. " What's wrong?" Ayato asked." My bat flew away! It took me forever to catch it" Kanato sniffled. " Don't worry, We'll catch it" Ayato said. Meanwhile, Baby Y/N was on the ground crawling. Subaru was just looking at the roses, Baby Y/N was crawling towards him and grabbed his foot. Subaru was surprised and backed away. He noticed it was his adopted baby sister." Leave me alone. Go play with someone else" Subaru sighed. Baby Y/N held out her arms towards him, " You want me to....pick you up?" Subaru asked. Y/N nodded her head and Subaru picks her up. Baby Y/N looks at the roses and laughs. " I can't believe I'm doing this" Subaru mumbled. He picks a rose and gives it to her. Baby Y/N grabs the rose and smiles, Subaru was rolling his eyes and grunted. Subaru felt something toward his sister, He felt a small blush on his face. Subaru placed the baby on the ground and left. Baby Y/N was looking at the rose, she started crawling away with the rose in her hands. Baby Y/N bumps into a figure and looks up. There was a tall purple-haired lady standing right in front of her. " Oh my! What do we have here?" she smirked. It was Cordelia, " An ugly mortal baby crawling around?" She picks up Y/N. Baby Y/N tilted her head at her. " So pure...." Cordelia bops her nose." Too bad I have to end you" she walks away with her. Baby Y/N drops her rose and started crying. In the distance, Ayato noticed his baby sister was being taken. He felt anger towards his mother. Ayato grunted while following his mother.