Maybe it's because the themes and emotions explored in rejected love manga resonate deeply with me. They often offer unique perspectives on relationships and human emotions.
The reason could be that the manga offers a refreshing take on romance and has unexpected twists and turns. Also, the art style might be very appealing.
First, try to communicate openly with your spouse about how you feel. Maybe your spouse can help mediate the situation. Second, be polite but firm when interacting with your in - laws. Don't encourage overly obsessive behavior. For example, if they are constantly hovering, limit the time you spend with them alone. Third, focus on building your own life and boundaries. If they cross those boundaries, gently remind them.
Maybe they see something special in you. It could be your kind heart, or your unique talents. In the novel, perhaps you represent a new hope or a fresh start for the family.
Another option is to limit your exposure to them. Don't be available all the time when they want to see you or interact. For example, if they call too often, you can let it go to voicemail sometimes. In the light novel, the main character might have faced a similar situation and found that creating a bit of distance helped ease the obsession.