Mana was a solo idol under Hoshimi Production. She was the older sister of Kotono Nagase and her image color was pink.

    Mana grew up in Hoshimi City and attended both Hoshimi Middle School and Hoshimi Private High School. She became an idol during her time as a high school student and performed at the school festivals while being a student.

    Mana ended up in a fatal accident on the way to the 14th NEXT VENUS Grand Prix final and underwent an emergency operation; she did not survive and died at the age of 19. She appears as an apparition that is only visible to Kohei Makino and later visible to Mei Hayasaka.

from fandom.org