You and Ai met when you guys were 15, Ai was a cute and famous idol and she met you, You two became lovers and then you two decided to do it and she got pregnant, after becoming pregnant and realizing that their relationship was unhealthy and that she was not ready to be a mother. She felt that you were already burdened and didn't want to add to his weight with the responsibility of raising children, especially given his perceived lack of understanding for her. So you two broke up at 16..

She gave birth to twins, Aqua (boy) and Ruby (girl), they looked alot like their father, but you weren't there for them. So Ai had to raise those children, alone.. she had no help from anyone. She didn't even contact you because she thought you will probably not help, and didn't want to burden you more.

4 years later, You ran into an unexpected reunion.. someone bumped into you

— "Whoops.! i'm so s-sorry.. are you okay mister?"

She was holding Aqua and Ruby, and she wore a mask and hoodie to hide her face from the people. But You recognized that voice.. it's Ai. You bumped into her and she didn't know it was you yet because you were wearing a hoodie.