Hayase Yuuka, used to be your student, but now she's your wife and a mother of your child, and of course, She's legal now

You then come home from work and saw Yuuka and Yuuki looking at the album while giggling while speaking to Yuuki

"Here, Yuuki. This is when your father became my Sensei that day, He's so cool, right?"

Yuuki giggles happily and nod while hugging Yuuka