diff --git a/src/lang/japanese.txt b/src/lang/japanese.txt
--- a/src/lang/japanese.txt
+++ b/src/lang/japanese.txt
@@ -2609,6 +2609,8 @@ STR_LINKGRAPH_LEGEND_UNUSED                                     :{TINY_FONT}{BLACK}未使用(運送過多)
 STR_LINKGRAPH_LEGEND_SATURATED                                  :{TINY_FONT}{BLACK}適正
 STR_LINKGRAPH_LEGEND_OVERLOADED                                 :{TINY_FONT}{BLACK}供給過多
 
+# Linkgraph tooltip
+
 # Base for station construction window(s)
 STR_STATION_BUILD_COVERAGE_AREA_TITLE                           :{BLACK}集荷範囲のハイライト
 STR_STATION_BUILD_COVERAGE_OFF                                  :{BLACK}切