Could you reword this for my Synopsis?
Yotsuyahi, previously known as Seisui, was born into a human family in a small town filled with highly intelligent scientists. From a young age, he had a deep fascination with space.
One day, a rumor spread throughout the town that a demon had killed and eaten an entire family who had gone to the river and never returned. This caused Seisui's parents to become paranoid and overly protective, closely monitoring him and his siblings at night. They even began accompanying them to the market, despite Seisui and his older brother Kazoku being capable of going alone.
On that fateful night, Seisui's parents went to gather water from the same river, despite their children's protests. When Seisui and Kazoku woke up, they realized their parents were still missing. Frantically searching the entire town, they were unable to find them. Suddenly, their father, Natsugumo, appeared, covered in blood and with scratches on his face. In shock, Seisui and his siblings guided their father home.
As Seihyo tended to their father's wounds, Seisui and Sakuhina desperately asked about their mother. Natsugumo, in tears, revealed that a horde of weak demons had attacked them, resulting in the swift death of their mother, Akiuta. Kazuko and Seihyo froze in horror, while Sakuhina sobbed uncontrollably.
Around two decades later, an unknown and mysterious illness claimed the life of Seisui's father. Overwhelmed by the suffering he had endured, Seisui left the town to study and become an official astrophysicist, seeking solace. However, his inner turmoil reached a breaking point when he received blood from Muzan, causing him to transform into a demon. Taking on the name Yotsuyahi, he joined the Twelve Kizuki, originally as the Lower Rank Four. Eventually, he rose to become the Upper Rank Three, resulting in the previous holder being demoted as a backup Upper Rank Three.