History
2006
August: Established
November: Founded
2007
November: "Houtai Pants" sold nationwide at United Arrows
2008
January: "Houtai Pants" launched at Isetan Shinjuku
May: Awarded the Men's EX Grand Prize by Sekai Bunka Publishing Inc. for "Men's EX"
July: Won the Best-selling Underwear Week Award for the first time at Isetan Shinjuku Main Store
November: Held the "Houtai no Jin" exhibition, the first exhibition of its kind ever held within the grounds of Togo Shrine in Harajuku, Tokyo. Announced "Kacchu Pants" (armor pants) inspired by Sengoku warlords at the same exhibition.
2009
June: Launched collaborative products with Callaway Golf
September: Exhibited at "WHO'S NEXT" in Paris, France
October: Held "Japants," the first ever underwear exhibition in the central hall of Mitsukoshi Main Store in Nihonbashi, Tokyo
At the same exhibition, announced "Aizome Houtai Pants" (indigo-dyed bandage pants) in collaboration with Akihito Sato, a Living National Treasure in indigo dyeing.
2010
January: "bj league Houtai Pants" launched as official Bj League underwear
Expanded to 18 shops in France, Italy, and Switzerland
February: Expanded to 18 shops in France, Italy, and Switzerland
May: Launched "Tigers Kacchu Pants" in collaboration with Hanshin Tigers
May: Won the Newcomer Award at the "National Department Store Buyers' Grand Prize" hosted by Senken Shimbun Co., Ltd.
August: Acquired two patents for the manufacturing and processing methods of "Houtai (HOHTAI®)"
September: Acquired trademark rights for "Houtai Pants"
2011
March: Launched in 120 Super Sports Xebio stores nationwide
August: World's first Houtai Pants without waistband elastic launched
August: Limited release of "BodyWild Houtai Pants" in collaboration with Gunze
2012
January: Selected for the Ministry of Economy, Trade and Industry's "Cool Japan" project, and held an exhibition in Shanghai, China
March: Launched "mxp Houtai Pants" in collaboration with Goldwin
October: Acquired "SIDO" trademark rights in Korea
November: Produced official apparel for Meishukai
2013
March: Launched "Houtai Yamitsuki Shorts" in collaboration with Nana Suzuki at Ito-Yokado stores nationwide
March: Launched Houtai Pants in collaboration with former Stussy designer Jody Barton
2014
March: LUCASFILM "STAR WARS" × "Houtai Pants" launched in department stores nationwide
March: Exhibited at "Health Expo 2014" at Tokyo Big Sight
October: Acquired patent for Houtai Pants "All-Round Type"
2015
April: Sponsored the 25th Challenge Fuji Five Lakes Ultra Marathon
September: "Kacchu Pants" adopted as stage costumes for American singer Madonna's "Rebel Heart Tour"
2018
February: Announced SIDO rebranding at the Spanish Embassy
March: Launched Houtai Shorts "Airrira" in collaboration with Wacoal
November: Exhibited in the medical and welfare corner at "New Value Creation Exhibition 2018" at Tokyo Big Sight
2019
January: Published "The Reason Why Japan's Small Underwear Shop is Loved by the World's Best"
March: Lecture at "Startup Cafe" at Osaka Umeda TSUTAYA
March: Started serialization of "If You Have a Business Card, Have a Story" in audiobook format
March: Started serialization of "Reiwa Edition 'Seven Samurai' Assemble! Warriors Challenging the World!!" in the "Magumagu" email magazine
April: Participated in the "KissTokyo" project at the request of the Tokyo Metropolitan Government
August: "Bwrap" launched at Ito-Yokado
October: Held "I am an Underwear Maker," the first lecture outside Japan, in LA
October: Exhibited at Industry Exchange Exhibition 2019
2021
April: Received a "Letter of Appreciation" from Ito-Yokado
2022
January: POOL collaboration "Asobi Houtai" pants released
February: Collaboration pants with Tadanori Yokoo released
March : Held login exhibition "Buttobi!"
2023
July: Launched "moffn," a sustainable patented safety bandage ball made from recycled bandage fabric scraps (waste material).
December: Houtai Pants registered as a local tax donation return gift in Yoshinogawa City, Tokushima Prefecture, their place of production.
2024
March: Relaunched "Kacchu Pants," incorporating Sengoku warlord designs.
July: Collaborated with emerging LA creator "Masa" to launch "GAMING UNDERGEAR," venturing into the metaverse, at Isetan Men's, Shinjuku.
December: Upgraded and relaunched the convenient cold-weather item "Neck Warmer."
2025
May: Takashi Toritani, former Hanshin Tigers player, launched "Etlis," a high-performance underwear brand utilizing Houtai Pants technology.
July-August: Entered the early childhood education field by launching a "digital detox-compatible story-based sticker book," supervised by Project Professor Akemi Miyasato of Ochanomizu University, at Ito-Yokado stores nationwide.
2026
March: To commemorate the 20th anniversary of "Houtai Pants®," they were certified as "disaster preparedness items" by the Disaster Preparedness and Safety Association, as "Disaster Preparedness Pants (disaster preparedness goods)" that can be cut with scissors for use as actual bandages in emergencies.
July: Launched "GRIZZMA," a new underwear brand resonating with YDIZZY of kiLLa crew.