You in the Folding Space

The hero and heroine, who had not seen each other for ten years, had already lost their innocence when they met again. The male protagonist grows up rapidly, while the female protagonist stays still. The male protagonist is the person who knows the female protagonist best, and the female protagonist is the bright spot in the male protagonist's heart. They put each other in the folded space of their life diary and secretly collected it. They shouldn't be close, but they secretly care about each other...