diff --git a/setting.json b/setting.json
index 3dd7676..659cad1 100644
--- a/setting.json
+++ b/setting.json
@@ -40,10 +40,15 @@
       "offset": [3.0, -0.8, 3.0, 1.5],
       "color": [196, 64, 0]
     },
-    "__others__": {
+    "/system": {
       "direction": "horizontal",
       "offset": [-0.5, -0.5, 1.0, 1.0],
+      "color": [64, 64, 128]
+    },
+    "__others__": {
+      "direction": "horizontal",
+      "offset": [0.5, -0.5, 1.0, 1.0],
       "color": [16, 64, 96]
     }
   }
-}
\ No newline at end of file
+}
diff --git a/src/dear_ros_node_viewer/caret2networkx.py b/src/dear_ros_node_viewer/caret2networkx.py
index bf73c0c..911dfc6 100644
--- a/src/dear_ros_node_viewer/caret2networkx.py
+++ b/src/dear_ros_node_viewer/caret2networkx.py
@@ -84,7 +84,7 @@ def parse_target_path(yml, node_name_list, topic_pub_dict, topic_sub_dict):
 def make_graph_from_topic_association(topic_pub_dict: dict[str, list[str]],
                     topic_sub_dict: dict[str, list[str]]):
   """make graph from topic association"""
-  graph = nx.DiGraph()
+  graph = nx.MultiDiGraph()
   for topic, node_pub_list in topic_pub_dict.items():
     if topic in topic_sub_dict:
       node_sub_list = topic_sub_dict[topic]
@@ -93,14 +93,14 @@ def make_graph_from_topic_association(topic_pub_dict: dict[str, list[str]],
       continue
     for node_pub in node_pub_list:
       for node_sub in node_sub_list:
-        # logger.debug(topic, node_pub, node_sub)
+        # logger.debug(f'{topic}, {node_pub}, {node_sub}')
         graph.add_edge(node_pub, node_sub, label=topic)
 
   return graph
 
 
 def caret2networkx(filename: str, target_path: str = 'all_graph',
-           ignore_unconnected=True) -> nx.classes.digraph.DiGraph:
+           ignore_unconnected=True) -> nx.classes.multidigraph.MultiDiGraph:
   """
   Create NetworkX Graph from architecture.yaml generated by CARET
 
@@ -115,7 +115,7 @@ def caret2networkx(filename: str, target_path: str = 'all_graph',
 
   Returns
   -------
-  graph : nx.classes.digraph.DiGraph
+  graph : nx.classes.multidigraph.MultiDiGraph
     NetworkX Graph
   """
 
diff --git a/src/dear_ros_node_viewer/setting.json b/src/dear_ros_node_viewer/setting.json
index 883cb31..659cad1 100644
--- a/src/dear_ros_node_viewer/setting.json
+++ b/src/dear_ros_node_viewer/setting.json
@@ -40,9 +40,14 @@
       "offset": [3.0, -0.8, 3.0, 1.5],
       "color": [196, 64, 0]
     },
-    "__others__": {
+    "/system": {
       "direction": "horizontal",
       "offset": [-0.5, -0.5, 1.0, 1.0],
+      "color": [64, 64, 128]
+    },
+    "__others__": {
+      "direction": "horizontal",
+      "offset": [0.5, -0.5, 1.0, 1.0],
       "color": [16, 64, 96]
     }
   }