diff --git a/unkf.lua b/unkf.lua
new file mode 100644
index 0000000..3513f1a
--- /dev/null
+++ b/unkf.lua
@@ -0,0 +1,43 @@
+local tr = aegisub.gettext
+
+script_name = tr"unkf"
+script_description = tr"replace kf/ko tags in selected lines by regular k tags"
+script_author = "amoethyst"
+script_version = "1.0"
+
+
+function split_line(subs, sel)
+    local expr_kof = "^(.-{[^}]*\\k)[of](.*)$"
+    local expr_K = "^(.-{[^}]*\\)K(.*)$"
+    local before, after
+
+    for _, i in ipairs(sel) do
+        line = subs[i]
+
+        -- replace ko and kf tags
+        while true do
+            before, after = line.text:match(expr_kof)
+            if before == nil then
+                break
+            else
+                line.text = before .. after
+            end
+        end
+
+        -- replace K tags
+        while true do
+            before, after = line.text:match(expr_K)
+            if before == nil then
+                break
+            else
+                line.text = before .. "k" .. after
+            end
+        end
+
+        subs[i] = line
+    end
+
+    aegisub.set_undo_point(script_name)
+end
+
+aegisub.register_macro(script_name, script_description, split_line)