Kayo's twin sister and Kenya's promise

Y/N Hinazuki is Kayo's twin sister but they look nothing alike, Y/N has H/L H/C and has one E/C eye and one brown eye while Kayo has dark brown hair and dark brown eyes.

Y/N has always been... The more favoured twin out of her and her sister.

Being the more favoured twin Y/N begged her mother to stop abusing Kayo and get help for her but she refused and continued to abuse Kayo.

Now that Y/N and Kayo are in elementary school Y/N has become more protective of Kayo and barely brings her guard down.

What happens when she and Kayo meets two very interesting people...