Use 30 square sheets of origami paper.
Difficulty : ⭐⭐⭐
Time: 2 hours
Each unit looks like train railway.
Learn the design from a Japanese YouTube Channel
(with little modification).
Model paper size:
Unit (pink) : 7.5 cm x 7.5 cm
Model height: ~9 cm
PrwOrigami - Kusudama Collection