Tomoe Saki is a weak and cowardly girl who only learns karate, but one night while going back home from school she quickly rescued a mysterious sunglasses person from a group of thugs, there the mysterious person gives Tomoe a yo-yo and chose her as the new Sukeban Deka. As tomoe feels complicated by her new position the yo-yo teleported her back to the showa era which is the 70’s where she encounters the original Sukeban Deka Saki Asamiya and help her take down some goons. Now Tomoe must go back and forth from the past to present and help Asamiya solve various cases that reflect on the present while trying to decide if she is worthy to take on the mantle of becoming the new Sukeban Deka.