Maru's father, Sagano, passed away when she was 12 years old, shortly after her birthday. The longstanding tension between the Hidaka (Ena) and Ikeda families, which had been ongoing since their engagement, became more pronounced.

Sagano, Maru's father, was a good person, but his family had issues from the beginning. The strong patriarchy and pride of the Ikeda family clashed with Hidaka's notable influence in society. The Ikeda family disapproved of Hidaka's influence and targeted Ena after Sagano's death. However, after the legal trials, Ena decided to leave the Ikeda name, taking Maru and Arata with her. The Hidaka family wanted to support Ena openly, but she declined to avoid tarnishing their name.

Ena underestimated the long-term consequences of her decision, unaware of the bullying Maru faced before and after the family name change. This worsens Maru's mental state who had not yet recovered from the mourning process after losing her grandfather and father, the two people closest to her. Maru chose to keep silent to avoid burdening her mother.

Maru, resembling her father in personality and appearance, experienced bullying at school. On the other hand, Arata, faced a more favorable reception due to his resemblance to his mother and the perceived strength of the Hidaka gene.

Arata, though introverted, was more socially adept and empathetic, gaining popularity at school. Maru, on the other hand, faced challenges as people bullied her, questioning her worthiness of the Hidaka surname.