diff --git a/kadai1/tanaka0325/README.md b/kadai1/tanaka0325/README.md
index dd5b852..e239401 100644
--- a/kadai1/tanaka0325/README.md
+++ b/kadai1/tanaka0325/README.md
@@ -24,7 +24,7 @@
 
 ```zsh
 # build
-$ go build -o ./imgconv
+$ go build -o imgconv ./cmd/imgconv
 
 # display help
 $ ./imgconv -h
diff --git a/kadai1/tanaka0325/imgconv.go b/kadai1/tanaka0325/imgconv.go
deleted file mode 100644
index badc036..0000000
--- a/kadai1/tanaka0325/imgconv.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package main
-
-import "github.com/gopherdojo/dojo8/kadai1/tanaka0325/converter"
-
-func main() {
-	converter.Convert()
-}
diff --git a/kadai1/tanaka0325/imgconv/cmd/imgconv/main.go b/kadai1/tanaka0325/imgconv/cmd/imgconv/main.go
new file mode 100644
index 0000000..344f749
--- /dev/null
+++ b/kadai1/tanaka0325/imgconv/cmd/imgconv/main.go
@@ -0,0 +1,9 @@
+package main
+
+import (
+	"github.com/gopherdojo/dojo8/kadai1/tanaka0325/imgconv"
+)
+
+func main() {
+	imgconv.Run()
+}
diff --git a/kadai1/tanaka0325/converter/conv_image.go b/kadai1/tanaka0325/imgconv/conv_image.go
similarity index 98%
rename from kadai1/tanaka0325/converter/conv_image.go
rename to kadai1/tanaka0325/imgconv/conv_image.go
index 2be5c9a..7a873e5 100644
--- a/kadai1/tanaka0325/converter/conv_image.go
+++ b/kadai1/tanaka0325/imgconv/conv_image.go
@@ -1,4 +1,4 @@
-package converter
+package imgconv
 
 import (
 	"fmt"
diff --git a/kadai1/tanaka0325/converter/exts.go b/kadai1/tanaka0325/imgconv/exts.go
similarity index 91%
rename from kadai1/tanaka0325/converter/exts.go
rename to kadai1/tanaka0325/imgconv/exts.go
index 5343d8d..ab81016 100644
--- a/kadai1/tanaka0325/converter/exts.go
+++ b/kadai1/tanaka0325/imgconv/exts.go
@@ -1,4 +1,4 @@
-package converter
+package imgconv
 
 import "errors"
 
diff --git a/kadai1/tanaka0325/go.mod b/kadai1/tanaka0325/imgconv/go.mod
similarity index 54%
rename from kadai1/tanaka0325/go.mod
rename to kadai1/tanaka0325/imgconv/go.mod
index 80a8fb1..ad64074 100644
--- a/kadai1/tanaka0325/go.mod
+++ b/kadai1/tanaka0325/imgconv/go.mod
@@ -1,4 +1,4 @@
-module github.com/gopherdojo/dojo8/kadai1/tanaka0325
+module github.com/gopherdojo/dojo8/kadai1/tanaka0325/imgconv
 
 go 1.14
 
diff --git a/kadai1/tanaka0325/go.sum b/kadai1/tanaka0325/imgconv/go.sum
similarity index 100%
rename from kadai1/tanaka0325/go.sum
rename to kadai1/tanaka0325/imgconv/go.sum
diff --git a/kadai1/tanaka0325/converter/convert.go b/kadai1/tanaka0325/imgconv/imgconv.go
similarity index 86%
rename from kadai1/tanaka0325/converter/convert.go
rename to kadai1/tanaka0325/imgconv/imgconv.go
index c5ee5c2..2edc0d1 100644
--- a/kadai1/tanaka0325/converter/convert.go
+++ b/kadai1/tanaka0325/imgconv/imgconv.go
@@ -1,4 +1,4 @@
-package converter
+package imgconv
 
 import (
 	"flag"
@@ -9,18 +9,23 @@ import (
 	"strings"
 )
 
-// flags
 var (
+	// flags
+	f      = flag.String("f", "jpg", "file extention before convert")
+	t      = flag.String("t", "png", "file extention after convert")
+	dryRun = flag.Bool("n", false, "dry run")
+
+	// allow extensions
 	allowedExts = exts{"png", "jpg", "jpeg", "gif", "bmp", "tiff", "tif"}
-	f           = flag.String("f", "jpg", "file extention before convert")
-	t           = flag.String("t", "png", "file extention after convert")
-	dryRun      = flag.Bool("n", false, "dry run")
 )
 
-// Convert is to convert image file format
-func Convert() {
-	// check options ext
+func init() {
 	flag.Parse()
+}
+
+// Run is to convert image file format
+func Run() {
+	// check options ext
 	to := strings.ToLower(*t)
 	from := strings.ToLower(*f)
 	targetExts := []string{to, from}
diff --git a/kadai1/tanaka0325/testdata/images/sample1.jpg b/kadai1/tanaka0325/imgconv/testdata/images/sample1.jpg
similarity index 100%
rename from kadai1/tanaka0325/testdata/images/sample1.jpg
rename to kadai1/tanaka0325/imgconv/testdata/images/sample1.jpg
diff --git a/kadai1/tanaka0325/testdata/images2/img/sample3.jpg b/kadai1/tanaka0325/imgconv/testdata/images2/img/sample3.jpg
similarity index 100%
rename from kadai1/tanaka0325/testdata/images2/img/sample3.jpg
rename to kadai1/tanaka0325/imgconv/testdata/images2/img/sample3.jpg
diff --git a/kadai1/tanaka0325/testdata/images2/sample2.jpg b/kadai1/tanaka0325/imgconv/testdata/images2/sample2.jpg
similarity index 100%
rename from kadai1/tanaka0325/testdata/images2/sample2.jpg
rename to kadai1/tanaka0325/imgconv/testdata/images2/sample2.jpg