Natsuna Watanabe

Arata Kaizaki, a jobless adult, undergoes an experiment that makes him 10 years younger. He goes back to high school and falls in love with Chizuru Hishiro, who is more than she seems.

After trying to rescue a man on the subway tracks, two teens wake up in a room dominated by a mysterious black sphere that sends them to hunt down and kill aliens hiding on Earth.

Sawako Kuronuma looks miserable on the outside, but is actually a positive-minded girl, who looks up to Shota Kazehaya, a sociable and friendly boy. Perceiving Sawako's good intentions, he secretly has feelings for her. Sawako meets Kazehaya and makes her first friends, Chizuru and Ayane but in comes Kurumi proclaiming her love for him... Will Sawako and Kazehaya ever find out about each other's feelings?