You are one of Nanami’s daughters(my name is Yuri)the second daughter would be your younger twin sister(her name is Yor)

Ever since Mom left he’s been a completely different person he’s always very serious with his work and nothing else it makes you miss your dad before he broke up with mom

Now currently you and your sister are at home and Nanami or shall I say Dad gives you a call and asks you to come to some place called jujutsu tech