Junya Sawamura is a minor character.
He's the son of Shinjirō and Yoshiko Sawamura, brother of Tatuya, grandson of Yoshito Sawamura, nephew of Giichirō Sawamura, Seisaburō Sawamura, and Rumi Satō, cousin of Yūta, and Anju.
Two years prior, Junya and his brother Tatsuya got scared when their grandpa Yoshito's broke in to rescue their cousin Anju from their home.
Junya and his family attend the grandpa Yoshito's funeral, and Junya and his brother Tatsuya just play games. They mock their cousin Anju. After Anju escaped, they later see her in a car with their uncle Seisaburō, and run to tell their father.