This work is made with acrylic paint and pen on foamed polystyrene. The case is made of wood and polystyrene. The work has a puzzle-like appearance. The inspiration for this work came from my previous iron works, which were inspired by the mating technique, the merging of objects as seen in crafts, and internal, abstract image drawings. The lines are made by playing with dripping acrylic paint and string. The letters "out" are concave on the border of the flat surface. They remain in the work as natural expressions and phenomena, as marks made by dripping, playing, and brush pressure. The blank space is a gap, and the space is expressed as an internal boundary. I used acrylic spray for the fine dots that can be seen on the surface. In the process of creating this work, I had a change of heart, a transition, and felt the ambiguity and connection between the inside and the outside, which led me to feel things such as subjectivity and objectivity, room and territory. This led me to create a work that has both the openness and comfort of an outdoor space and the comfort of a relaxing indoor space. The material polystyrene foam is light, soft, and delicate, making it difficult to handle, but it gives the work a soft impression. Also, the countless air bubbles inside the structure are interesting from a spatial point of view.