About myself

Japanese, Male. Programmer.


PHP, Web application, Web API, Internet, Linux, Server Operations, Photo, Single-lens reflex camera


関戸(せきど) 亮介(りょうすけ)
Ryosuke SEKIDO
关户 亮介 (Guānhù Liàngjiè)


1986-07-18. 33 (0x21) years old.


Please send to ryosuke@sekido dot info, IN JAPANESE. And my public key.


  1. 1990-04 - 1993-03: Miura Kindergarten, 三浦幼稚園
  2. 1993-04 - 1999-03: Hasse Elementary School, 三浦市立初声小学校
  3. 1999-04 - 2002-03: Hasse Junior High School, 三浦市立初声中学校
  4. 2002-04 - 2005-03: Kanagawa Sohgoh High School, 神奈川県立神奈川総合高等学校
  5. 2005-04 - 2009-03: Faculty of Environmental Information Studies, Keio University, 慶應義塾大学環境情報学部


  1. 2001-05: NTT Communications, .com Master ★ 2001
  2. 2004-05: JITEC, Fundamental Information Technology Engineer, 基本情報技術者
  3. 2005-09: Driving License, 普通運転免許
  4. 2007-12: JITEC, Technical Engineer (Network Systems), テクニカルエンジニア (ネットワーク)
  5. 2009-11: ETS TOEIC, 535 (Listening: 330 / Reading: 205)
  6. 2010-06: JITEC, Applied Information Technology Engineer, 応用情報技術者
  7. 2010-07: ETS TOEIC, 485 (Listening: 275 / Reading: 210)
  8. 2010-10: PHP技術者認定機構 Certified PHP 5 Engineer Novice, PHP5技術者認定試験
  9. 2012-05: ETS TOEIC, 575 (Listening: 325 / Reading: 250)


  1. Programming, プログラミング
  2. Photo taking, 写真: Canon EOS Kiss X2, EF-S 18-55mm F3.5-5.6 IS, EF 35mm F2, EF-S 60mm F2.8 Macro USM


  1. 2007-05: Web API 実践リファレンスブック, 加藤 貴之, 佐久間 勇樹, 関戸 亮介, いわさき ゆうだい, 毎日コミュニケーションズ

About computer skills


In 1994, 書院 (Shoin) manufactured by Sharp is a my first word processor. I can not write documents but just draw a picture because I do not know how to input it with Romaji.

In 1996, my first computer is Apple's Macintosh, maybe it is MacOS 8. It has 33.6kbps Analog Modem for the Internet connectivity, so I setup it to connect the net as soon as get it, with my father. However, I just crowing some portal sites, like Apple and goo. Sometime I read its HTML source, and study HTML. Finaly, I can write simple HTML.

In 1999, the first PC/AT comes my home. It has Windows 98, Intel Celeron 400MHz, 64MB RAM, 6.4GB HDD and 56kbps Analog Modem. Just this time, some people have personal homepages and install Perl BBS to there. So I download Perl CGI, and study Perl Programming.

In 2001, I wonder I can create programs with something for that computer. So I buy a basic C language programming book, and study it with Borland's C Compiler. And in this year, Google comes to Japan (supports Japanese language), so I change main search engine from goo to Google.

In 2002, I met Linux and PHP. And I get XREA's account for the first time. I install Redhat Linux 7.3 to the computer, and learn bash and basic Linux system. Next year, I can operate my home server, but only web service.

Programming Skills

  1. C
  2. C#
  3. HTML
  4. Java
  5. JavaScript
  6. PHP
  7. Perl
  8. Python
  9. Ruby
  10. sh

Above list are UNIX sorted. I often use PHP for developing web applications. However, programs which are not need to communicate with web browsers, are written with sh, Perl or Python. I use C# only to make Windows applications, so very rare case.

Find me in the real world


  1. 2010-07-08: JANOG26, ORG (web team)
  2. 2011-07-14: JANOG28, ORG chair


  1. 2008-07-20: VimM#1
  2. 2008-07-21: PHP カンファレンス 2008
  3. 2008-08-02: ハチロクお食事会オフ@東京の沖縄
  4. 2008-08-13: セキュリティ&プログラミングキャンプ 2008
  5. 2008-09-06: VimM#2
  6. 2008-12-21: 2008年度ハチロク忘年会
  7. 2009-12-12: ハチロク世代2009年忘年会
  8. 2009-12-13: 餃子部 ー 蒲田遠征編

Find me on the web

Web sites

  1. ryosuke.sekido.info, 関戸亮介.jp, せきどねこ.jp
  2. c--v.net, a domain for private works
  3. web.sfc.keio.ac.jp/~t05562rs/, on Keio University, SFC CNS
  4. www.tom.sfc.keio.ac.jp/~sekido/, on Hagino/Hattori laboratory


  1. mixi (Japanese)
  2. GREE (Japanese)
  3. Twitter
  4. Flickr
  5. Rejaw
  6. Delicious
  7. Facebook
  8. Google+

Web services

  1. iTwit.jp, a Twitter client for NTT DoCoMo mobile phone