Randoseru Air model is the lightweight model of the modern Japanese randoseru backpacks, focusing on features like "Angel's Wing" padding, memory foam, and air permeability. Designed by SEIBAN (Tenshi no Hane) to reduce burden for elementary kids, with models like the Sugo-Karu Air weighing under 1kg. 

These bags use advanced materials like Clarino leather for durability and lightness, plus decompression designs, making them "less burdensome and easier to carry".

Key Features in Randoseru Air:

• Lightweight Materials: Use of synthetic leather (Clarino) and special construction (Tough Compact) to reduce weight, with some models typically under 1kg.
• Weight Dispersion: "Angel's Wing" shoulder belts and D-layered back cushions help distribute weight evenly.
  
• Breathability: High-resistance memory foam and ventilation create air permeability, keeping the back cooler.
  
• Ergonomic Design: Focus on soft yet firm back support and decompression to ease the load.