To start making an origami gun, you'll need to prepare two sheets of paper. Take a large rectangular sheet of origami paper. Fold it in half and tear it into two smaller, wider rectangles. You will fold each smaller sheet using the following process:  Fold the rectangle in half from top to bottom, creating a smaller, narrower rectangle. Then, unfold the paper.  Use the crease in the center of the paper as a guide. The paper is now in two halves. Fold one-half inward, so the end of the paper lines up with create. Then, fold the other half inward, so the end of the paper lines up with crease. The two ends of the paper should meet at the crease of the paper.  Now, fold the paper inward along the crease. You should have a long, thin strip of folded paper. Then, unfold the paper. The crease at the center of the strip should divide it into two halves. Fold the end of the right half at a 90-degree angle. Then, fold the other half into a 90-degree angle. The paper should look something like a small paper horseshoe. The width of the center, horizontal section should be twice the width of your long pieces. Place the strip to the right of your center line. Then fold the "arm" of the horseshoe right where it meets the thin strip in the center. Keeping the fold starting in the same place, re-angle the horseshoe so it looks a bit like a squared teardrop. There should be a nice triangle in the middle. It will be a bit like a lower-case "L," with a long strip and slight curvy bit at the end. You should also fold your long, thin strip of paper in half too. Things can get a bit tricky here, so go slowly. Take your second strip of paper and fold it in half from end to end. You will be inserting this strip into the handle:  Pull the handle apart slightly. The bent down portion should have two small openings. Feed either end of the second strip through these openings.  Pull both ends of the second folded strip through the openings of the horseshoe. Keep pulling until the two strips are forming a wide angle of roughly 110 degrees....

TL;DR in Vietnamese:
Chuẩn bị hai mảnh giấy và gấp chúng thành hai dải mỏng và dài. Gấp một dải giấy thành hình móng ngựa. Gấp lại chân của móng ngựa sao cho chúng bắt chéo vào trong. Gấp đôi hình tam giác, miết để có dạng "tay cầm" phẳng cho súng của bạn. Luồn dải giấy kia vào dải đầu tiên bằng cách cho đầu giấy vào phần mở của tay cầm. Điều chỉnh cho đến khi súng có cò, dùng ghim bấm cố định tay cầm và nòng súng. Dùng dao chuyên dụng khoét một miếng nhỏ khoảng 1 cm ngay trên tay cầm súng. Cắt một vết nhỏ ở nòng súng. <finished>