1. Align the right and left sides of the paper and fold it. 2. Align the upper and lower sides of the paper with the crease on the left, leave the crease, and then open it. 3. Align the upper edge with the newly folded oblique crease, and open it after leaving the crease. 4. Align the midpoint on the right with the point just folded, fold the upper part down, press out the crease and open it. 5. Align the lower right part with the horizontal crease folded in the fourth step, press out the crease and open it, so that the new oblique crease and the oblique crease folded in the first part form a long strip. 6. Fold up the oblique crease at the top left 1/4 of the note, press out only the crease in the middle part, and open it. 7. Fold up the oblique crease in the lower right corner aligned with step 6, and then open it. 8. Open the paper completely, fold the top edge at the top corner, leaving a crease, and then open it. 9. Fold the paper to the left along the first triangular crease, the second triangular crease and the third triangular crease. 10. Pull aside, align the upper corner of the inner strip with the valley crease, open one side, flatten the bulge along the crease, flatten the lower strip into a triangle, and flatten the upper part. 1 1. Align the midpoint of the lower edge with the vertex and flatten the left and right sides. 12. Fold the lower left and right sides inward. 13. Fold the left tail backwards, and the upper part of the right tail will be broken, leaving a crease and then pulling it apart. 14. Fold and align the points on the left with the points on the right of the middle bar, then fold along the left side of the bar to the left, and do the same for the right side. 15. Fold the lower right corner of the left fin obliquely, pull the inner side upward, then fold the left side to the right and flatten the upper side. 16. Fold the upper corner diagonally and pull down the lower edge to fold the left fin. 17. Fold the right fin in the same way. 18. Fold one side of the fish mouth, open the mouth, separate the upper and lower layers, and treat the other side equally. 19. Press out two creases on the body below the fins, fold them inward, bulge the back of the fish, and fold the lower part into the interlayer. The other side does the same. 20. Fold the fin outward and fold the fin line into a fan shape. 2 1. Fold the lines of fish dorsal fin by fan folding method. 22. Stick the fishtail with double-sided adhesive tape, bend the fishtail to the left and reshape the details, so that a Maberna koi fish can be folded. Do you know that?/You know what? Koi fish is an advanced ornamental fish popular in the world today. It has the reputation of "living gem in water" and "swimming art".