In a karaoke room filled with balloons, confetti and cake, a 34-year-old woman dances with a dozen friends celebrating her “rebirth of the past”. The woman, who posts on Chinese social media under the name Sushi, had just ended her four-year marriage. Shaking off social stereotypes around divorce that suggest she should feel shame and failure, she decided to throw a party with all of her girlfriends. She put on a favourite black dress from the time before she met her husband, to honour that she was “getting back to…