1997 April Established OpenDoor, Inc. in Mita, Minato-ku, Tokyo
August Launched travel comparison site "Travelko-chan"
Launched Travelko-chan "overseas tour search service"
  Launched Travelko-chan "overseas airline ticket search service"
2000 June Launched Travelko-chan "domestic tour search service"
2001 March Relocated headquarters in Akasaka, Minato-ku, Tokyo
2002 July Launched mobile phone contents "RPGDS"
2003 May Became member of Japan Business Federation
July Relocated headquarters within Akasaka, Minato-ku, Tokyo
  Launched mobile phone contents "Free game DS"
2004 December Launched Travelko-chan "domestic accommodations search service"
2005 June Launched mobile phone contents "Game DS"
2006 November Acquired the Privacy Mark of Japan's privacy mark system
2010 January Launched Travelko-chan overseas accommodations search service
2011 October Established Osaka office In Sonezakishinchi, Kita-ku, Osaka-shi, Osaka
November Relocated headquarters within Akasaka, Minato-ku, Tokyo
2013 January Launched Travelko-chan domestic airline ticket search service
  June Launched Travelko-chan domestic dynamic package search service
2014 January Launched Travelko-chan overseas dynamic package search service
  Launched Travelko-chan overseas local reviews service
March Acquired subsidiary company stock of Hotel Skip Co.,Ltd
April Acquired the Kurumin mark (Certification mark for companies that provide support to families raising children.)
October Launched multi-language travel comparative site "HOTELSAURUS" for global market 
  Launched HOTELSAURUS airline search service
  Launched GALLERY JAPAN Japanese traditional art and crafts site
2015 April Launched HOTELSAURUS airline ticket search service
May Launched HOTELSAURUS Local reviews service for Japan
December Opendoor listed on the Tokyo Stock Exchange mothers market
2016 June Multi-language travel comparison site "HOTELSAURUS" renamed to "Travelko"
December OpenDoor transferred from Mothers to 1st section market on the Tokyo Stock Exchange
2017 January Travel comparison site "Travelko-chan" renamed to "Travelko"
July Relocated headquarters within Akasaka, Minato-ku, Tokyo (present address)