birthdate: '1975-11-16'
birthplace: Kushiro City, Hokkaido, Japan
discography:
- catalog: ZMCZ-3040
  date: '2006-10-25'
  link: album/59956
  reprint: false
  roles:
  - Illustrator
  - Character Designer
  titles:
    en: Happiness! / Ayumi Murata
    ja: はぴねす! / 村田 あゆみ
    ja-latn: Happiness! / Ayumi Murata
  type: game
- catalog: ZMCZ-3041
  date: '2006-10-25'
  link: album/59955
  reprint: false
  roles:
  - Cover Illustrator
  titles:
    en: Magical★Generation / Yui Sakakibara
    ja: マジカル★ジェネレーション / 榊原 ゆい
    ja-latn: Magical★Generation / Yui Sakakibara
  type: game
- catalog: ZMCZ-3400
  date: '2007-06-06'
  link: album/63770
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD Series
      Vol.1 Rinna Sawaki (cv. Satomi Koorogi) [Limited Edition]
    ja: TVアニメ「この青空に約束を― ～ようこそつぐみ寮へ～」キャラクターソングCDシリーズ Vol.1 沢城凛奈 (cv.こおろぎさとみ) [BOX付初回限定版]
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD
      Series Vol.1 Rinna Sawaki (cv. Satomi Koorogi) [Limited Edition]
  type: anime
- catalog: ZMCZ-3401
  date: '2007-06-06'
  link: album/63772
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD Series
      Vol.1 Rinna Sawaki (cv. Satomi Koorogi)
    ja: TVアニメ「この青空に約束を― ～ようこそつぐみ寮へ～」キャラクターソングCDシリーズ Vol.1 沢城凛奈 (cv.こおろぎさとみ)
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD
      Series Vol.1 Rinna Sawaki (cv. Satomi Koorogi)
  type: anime
- catalog: ZMCZ-3402
  date: '2007-06-06'
  link: album/63771
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD Series
      Vol.2 Umi Hayama (cv. Fumi Morisawa)
    ja: TVアニメ「この青空に約束を― ～ようこそつぐみ寮へ～」キャラクターソングCDシリーズ Vol.2 羽山海己 (cv.森沢芙美)
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD
      Series Vol.2 Umi Hayama (cv. Fumi Morisawa)
  type: anime
- catalog: ZMCZ-3403
  date: '2007-06-20'
  link: album/63774
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD Series
      Vol.3 Naoko Asakura (cv. Ai Orikasa)
    ja: TVアニメ「この青空に約束を― ～ようこそつぐみ寮へ～」キャラクターソングCDシリーズ Vol.3 浅倉奈緒子 (cv.折笠愛)
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD
      Series Vol.3 Naoko Asakura (cv. Ai Orikasa)
  type: anime
- catalog: ZMCZ-3404
  date: '2007-06-20'
  link: album/63781
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD Series
      Vol.4 Miyaho Rokujo (cv. Junko Nakata)
    ja: TVアニメ「この青空に約束を― ～ようこそつぐみ寮へ～」キャラクターソングCDシリーズ Vol.4 六条宮穂 (cv.中田順子)
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD
      Series Vol.4 Miyaho Rokujo (cv. Junko Nakata)
  type: anime
- catalog: ZMCZ-3405
  date: '2007-07-04'
  link: album/63782
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD Series
      Vol.5 Shizu Fujimura (cv. Hitomi)
    ja: TVアニメ「この青空に約束を― ～ようこそつぐみ寮へ～」キャラクターソングCDシリーズ Vol.5 藤村 静 (cv.ひと美)
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD
      Series Vol.5 Shizu Fujimura (cv. Hitomi)
  type: anime
- catalog: ZMCZ-3406
  date: '2007-07-04'
  link: album/63783
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD Series
      Vol.6 Akane Mitamura (cv. Kaori Nazuka)
    ja: TVアニメ「この青空に約束を― ～ようこそつぐみ寮へ～」キャラクターソングCDシリーズ Vol.6 三田村 茜 (cv.名塚佳織)
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Character Song CD
      Series Vol.6 Akane Mitamura (cv. Kaori Nazuka)
  type: anime
- catalog: ZMCZ-3539
  date: '2007-09-21'
  link: album/6531
  reprint: false
  roles:
  - Character Designer
  titles:
    en: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Piano Stories
    ja: この青空に約束を― ~ようこそつぐみ寮へ~ Piano Stories
    ja-latn: Konoaozora ni Yakusoku wo ~Youkoso Tsugumi-Ryo he~ Piano Stories
  type: anime
- catalog: AVCA-29378/B
  date: '2009-10-28'
  link: album/58934
  reprint: false
  roles:
  - Chief Animator
  titles:
    en: 'EleC☆TriCk / Rona (CV: Aya Hirano)'
    ja: 'EleC☆TriCk / Rona (CV: Aya Hirano)'
    ja-latn: 'EleC☆TriCk / Rona (CV: Aya Hirano)'
  type: anime
- catalog: LASA-5046
  date: '2010-05-26'
  link: album/26696
  reprint: false
  roles:
  - Jacket Illustrator
  titles:
    en: Ichiban Ushiro no Daimaou Drama & Character Song Album ~Ichiban Ushiro ni
      Aru Kimochi~
    ja: いちばんうしろの大魔王 ドラマ&キャラクターソングアルバム ～いちばんうしろにあるキモチ～
    ja-latn: Ichiban Ushiro no Daimaou Drama & Character Song Album ~Ichiban Ushiro
      ni Aru Kimochi~
  type: anime
- catalog: PCCG-02263
  date: '2023-08-02'
  link: album/129916
  reprint: false
  roles:
  - Illustrator
  titles:
    en: '#DREAMS are fleeting, fall in LOVE, girls! / Aika Natsukawa (CV: Akiho Suzumoto)'
    ja: '#夢は短し恋せよ乙女 / 夏川愛華 (CV: 涼本あきほ)'
    ja-latn: '#Yume wa Mijikashi Koiseyo Otome / Aika Natsukawa (CV: Akiho Suzumoto)'
  type: anime
featured_on: []
info:
  Birthdate: Nov 16, 1975
  Birthplace: Kushiro City, Hokkaido, Japan
  Credited works: 13 albums in database
  Credits:
  - 9 character designer
  - 2 illustrator
  - 1 cover illustrator
  - 1 chief animator
  - 1 jacket illustrator
  Organizations: &id001
  - link: org/4488
    names:
      en: AXsiZ
      ja: 株式会社AXsiZ
link: artist/69970
meta:
  added_date: 2025-03-09T22:50
  edited_date: 2025-03-09T22:50
  fetched_date: 2026-01-11T17:08
  ttl: 86400
  visitors: 169
name: Masaru Koseki
name_real: 小関 雅
name_trans: こせき まさる
notes: 'Japanese animator, animation director & character designer.

  Currently affiliated with AXsiZ (January 28, 2019 ~ present).

  Previously an artistic director at Artland.'
organizations: *id001
sex: male
type: Individual
vgmdb_link: https://vgmdb.net/artist/69970?perpage=99999
websites:
  Official: []
  Personal: []
  Reference: []
