Y/N attended Aboa Johsai during her 2nd year. She was approached by her brother, Iwaizumi Hajime, who was a year older than her, to help out with the boys' volleyball team. Y/N agreed to help her brother by filling water bottles, running drills, and eventually becoming the Team Manager. One day, Y/N, however, was messaged by a random guy on the Aboa Johsai volleyball team asking about some science work.