The copywriting... I have a headache.
The source of inspiration for this novel is "Fullmetal Alchemist". There is such a concept - equivalent exchange. If you want to get something, you must lose something of equal value. In fact, this is also the concept of life, isn't it? But is this really the case? When you love someone with all your heart, but only get a small reward in return, you will suddenly realize that this world is originally composed of all kinds of inequalities.