use organization prefixed namespace

composer.json

@@ -5,20 +5,25 @@
     "wordpress",
     "plugin"
   ],
-  "homepage": "https://github.com/kodansha/killer-pads",
+  "type": "wordpress-plugin",
   "authors": [
     {
-      "name": "Kodansha Ltd.",
+      "name": "KODANSHA Ltd.",
       "homepage": "https://github.com/kodansha"
+    },
+    {
+      "name": "Hirofumi Wakasugi",
+      "homepage": "https://github.com/5t111111"
     }
   ],
-  "type": "wordpress-plugin",
+  "homepage": "https://github.com/kodansha/killer-pads",
+  "license": "GPL v2 or later",
   "require": {
     "php": ">=7.3"
   },
   "autoload": {
     "psr-4": {
-      "KillerPads\\": "src"
+      "Kodansha\\KillerPads\\": "src/"
     }
   }
 }

killer-pads.php

@@ -20,10 +20,18 @@
     require_once __DIR__ . '/vendor/autoload.php';
 }
 
-(new KillerPads\AdminPad())->init();
-(new KillerPads\RestRoutesPad())->init();
-(new KillerPads\SecurityPad())->init();
+/**
+ * Initialize plugin
+ */
+function init()
+{
+    (new Kodansha\KillerPads\AdminPad())->init();
+    (new Kodansha\KillerPads\RestRoutesPad())->init();
+    (new Kodansha\KillerPads\SecurityPad())->init();
 
-if (!(defined('KILLER_PADS_ENABLE_COMMENTS') && KILLER_PADS_ENABLE_COMMENTS == true)) {
-    (new KillerPads\CommentsPad())->init();
+    if (!(defined('KILLER_PADS_ENABLE_COMMENTS') && KILLER_PADS_ENABLE_COMMENTS == true)) {
+        (new Kodansha\KillerPads\CommentsPad())->init();
+    }
 }
+
+add_action('plugins_loaded', 'init', PHP_INT_MAX - 1);

src/AdminPad.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace KillerPads;
+namespace Kodansha\KillerPads;
 
 class AdminPad
 {

src/CommentsPad.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace KillerPads;
+namespace Kodansha\KillerPads;
 
 /**
  * Completely disable comments in WordPress

src/RestRoutesPad.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace KillerPads;
+namespace Kodansha\KillerPads;
 
 use WP_Error;
 

src/SecurityPad.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace KillerPads;
+namespace Kodansha\KillerPads;
 
 class SecurityPad
 {