My answer might be a little vague. You mentioned a Japanese manga," Spring Night is Short, Girl, March On." The main character of this manga was a young man named Yamada Taro. He had a servant named Kaho. In the story, Yamada Taro gradually developed feelings for Kaho, but he was troubled by his engagement with his fiancée Sae. Sae, on the other hand, wanted to use Taro Yamada's relationship with Kaho to achieve her goal. In the end, Taro Yamada decided to give up everything and marry Sae, but he couldn't forget Kaho.