Unicharm announced on May 27, 2026, that a summer-limited version of Lifree's ultra-thin, underwear-style pull-on pants would reach stores across Japan from late May. It features a sweat-absorbing sheet around the buttocks that the company says absorbs and spreads perspiration before drying it. Unicharm reports ten times faster drying and an internal diaper temperature 2°C lower than its previous product.
The design also reduces waist-area thickness to half that of the company's previous version, with a streamlined construction extending through the crotch. Unicharm presents these changes as a response to demand for less stuffiness and discomfort during prolonged hot weather. Its survey found that 51% considered avoiding stuffiness important when choosing pull-on diapers, while 45% prioritised avoiding skin irritation.
The range has two absorbency options: the version labelled for two urinations comes in S through LL, while the four-urination version comes in M and L. Multiple pack sizes are listed, and prices are open rather than manufacturer-set.