Life for 17-year-old Konno Makoto is filled with fun days at school and hanging out with her two best friends, Chiaki and Kousuke. But then she finds herself with an ominous ability to leap back in time. A truly strange ability that at first saves her life, but then allows her to not be late at school, to know the answers on any surprise exams and to avoid any troublesome mishaps. It is only when Makoto chooses to use this ability to avoid some of the more personal issues that arise with her friends, that events become both complex and painfully difficult — the simple gift that she began to take for granted suddenly becomes a troublesome burden.

[Source: AniDB]