The design is inspired by Doraemon's four-dimensional pocket. I find it interesting that a large tool comes out of a small pocket, and I quote that surprise in the front pocket of my backpack. The lining of the small pocket has an extra-large gusset that can be used to store items that should not fit in the front pocket (lunch boxes, plastic bottles, canned beer, etc.). The appearance is simple, and it has a modern finish by cutting the stitches as much as possible. By denting the front pocket inward, it transforms into a strange shape.