Riisa Naka (born on October 18, 1989 in Nagasaki prefecture) is a Japanese actress. She was given a Best New Talent award at the 2009 Yokohama Film Festival. Naka became famous for appearing in Hachi One Diver.
When 17-year-old Makoto Konno gains the ability to, quite literally, 'leap' backwards through time, she immediately sets about improving her grades and preventing personal mishaps. However, she soon realises that changing the past isn't as simple as it seems, and eventually, will have to rely on her new powers to shape the future of herself and her friends.
Akari Yoshiyama is graduating high school soon and is expected to lead new life after she passes the university entrance exam, while her mother is working as a pharmacologist. However, her mother has a car accident and the situation is totally changed. She decides to go to 1972 to fullfil her mother's wish.
Teenage math whiz Kenji Koiso agrees to take a summer job at the Nagano hometown of his crush, Natsuki. When he arrives, he finds that her family have reunited to celebrate the 90th birthday of their matriarch. His job: pretend to be Natsuki's fiancé. Meanwhile, his attempt to solve a mathematical equation causes a parallel world's collision with Earth.