A full rotation backward. The setting is a “backflip class,” which is currently gaining popularity. Mixed in with the children are office workers and housewives struggling on the mats after work. A man in his 40s who has always admired Jackie Chan. A father who wants to show off to his daughter. A young woman who started attending because she thought it might be useful for her job. If you can do a backflip, will your life turn around? Three days at this slightly unusual class.