The book,"Quick Wear: A Strategy for Morbid Loyal Dogs", meets your requirements! When the female protagonist, Sheng Ronghua, was on a mission, she met the deep well of ice who wanted to catch her and fall in love with her. The male protagonist was affectionate and loyal, while the female protagonist was a little sick. This is a sci-fi novel about space-time travel. I recommend it to you! I hope you like my recommendation. Muah ~