The lining is all polka dots, so you can roll it up to your preferred position, once or twice! You can wear it for a long time, starting from size 80♪ I think it can be worn by both boys and girls^_^ There's no opening to replace the elastic in the waist. If it's loose, use suspenders, etc.^_^ #tsuttsuGirls90size #tsuttsuBoys90size