diff --git a/holidays/plan2/holiday_jp_en-us b/holidays/plan2/holiday_jp_en-us
--- a/holidays/plan2/holiday_jp_en-us
+++ b/holidays/plan2/holiday_jp_en-us
@@ -3,10 +3,11 @@
 ::
 :: Author:   Toyohiro Asukai <toyohiro@ksmplus.com>
 ::           Jumpei Ogawa <phanective@gmail.com>
+::           Firas Kraiem <firas@fkraiem.org>
 ::
 :: Language: English
 ::
-:: Updated:  2017-05-07
+:: Updated:  2018-07-16
 ::
 :: Source:   http://www8.cao.go.jp/chosei/shukujitsu/gaiyou.html
 ::           http://www.nao.ac.jp/faq/a0301.html
@@ -112,22 +113,39 @@
 "Labor Thanksgiving Day"           public on november 23
 "The Emperor's Birthday"           public on december 23
 
-:: If a "National Holiday" is on Sunday,the following day
-:: shall be a substitute holiday.
+:: If a "Public Holiday" is on a Sunday, the first following day which
+:: is not a "Public Holiday" shall be a substitute holiday. If a day
+:: which is not a "Public Holiday" is between two "Public Holidays",
+:: it shall be a holiday. Those holidays are not legally "Public
+:: Holidays" (so in particular not for the purpose of determining such
+:: holidays), but they are identical in practice.
 "Substitute holiday"               public on march 21 2005
 "Substitute holiday"               public on january 2 2006
 "Substitute holiday"               public on february 12 2007
 "Substitute holiday"               public on april 30 2007
 "Substitute holiday"               public on september 24 2007
 "Substitute holiday"               public on december 24 2007
 "Substitute holiday"               public on november 24 2008
 "Substitute holiday"               public on march 22 2010
+"Substitute holiday"               public on january 2 2012
+"Substitute holiday"               public on april 30 2012
+"Substitute holiday"               public on december 24 2012
+"Substitute holiday"               public on may 6 2013
+"Substitute holiday"               public on november 4 2013
+"Substitute holiday"               public on may 6 2014
+"Substitute holiday"               public on november 24 2014
+"Substitute holiday"               public on may 6 2015
 "Substitute holiday"               public on march 21 2016
 "Substitute holiday"               public on january 2 2017
 "Substitute holiday"               public on february 12 2018
 "Substitute holiday"               public on april 30 2018
 "Substitute holiday"               public on september 24 2018
 "Substitute holiday"               public on december 24 2018
+"Substitute holiday"               public on may 6 2019
+"Substitute holiday"               public on august 12 2019
+"Substitute holiday"               public on november 4 2019
+
+"Holiday"                public on september 22 2015
 
 :: Religious
 
diff --git a/holidays/plan2/holiday_jp_ja b/holidays/plan2/holiday_jp_ja
--- a/holidays/plan2/holiday_jp_ja
+++ b/holidays/plan2/holiday_jp_ja
@@ -3,10 +3,11 @@
 ::
 :: Author:   Toyohiro Asukai <toyohiro@ksmplus.com>
 ::           Jumpei Ogawa <phanective@gmail.com>
+::           Firas Kraiem <firas@fkraiem.org>
 ::
 :: Language: Japanese
 ::
-:: Updated:  2017-05-07
+:: Updated:  2018-07-16
 ::
 :: Source:   http://www8.cao.go.jp/chosei/shukujitsu/gaiyou.html
 ::           http://www.nao.ac.jp/faq/a0301.html
@@ -22,7 +23,7 @@
 
 :: Public Holidays
 :"New Year's Day"
-"元旦"                               public on january 1
+"元日"                               public on january 1
 :"Coming of Age Day"
 "成人の日"                            public on second monday in january
 :"National Foundation Day"
@@ -120,23 +121,39 @@
 :"The Emperor's Birthday"
 "天皇誕生日"                          public on december 23
 
-:: If a "National Holiday" is on Sunday,the following day
-:: shall be a substitute holiday.
-:"Substitute holiday"
+:: If a "Public Holiday" is on a Sunday, the first following day which
+:: is not a "Public Holiday" shall be a substitute holiday. If a day
+:: which is not a "Public Holiday" is between two "Public Holidays",
+:: it shall be a holiday. Those holidays are not legally "Public
+:: Holidays" (so in particular not for the purpose of determining such
+:: holidays), but they are identical in practice.
 "振替休日"                            public on march 21 2005
 "振替休日"                            public on january 2 2006
 "振替休日"                            public on february 12 2007
 "振替休日"                            public on april 30 2007
 "振替休日"                            public on september 24 2007
 "振替休日"                            public on december 24 2007
 "振替休日"                            public on november 24 2008
 "振替休日"                            public on march 22 2010
+"振替休日"                            public on january 2 2012
+"振替休日"                            public on april 30 2012
+"振替休日"                            public on december 24 2012
+"振替休日"                            public on may 6 2013
+"振替休日"                            public on november 4 2013
+"振替休日"                            public on may 6 2014
+"振替休日"                            public on november 24 2014
+"振替休日"                            public on may 6 2015
 "振替休日"                            public on march 21 2016
 "振替休日"                            public on january 2 2017
 "振替休日"                            public on february 12 2018
 "振替休日"                            public on april 30 2018
 "振替休日"                            public on september 24 2018
 "振替休日"                            public on december 24 2018
+"振替休日"                            public on may 6 2019
+"振替休日"                            public on august 12 2019
+"振替休日"                            public on november 4 2019
+
+"休日"                               public on september 22 2015
 
 :: Religious