"Onatan! is a high school detective eroge from Tower of Desire
with artwork by Penta Aogiri, voiced by Kanari Kanzaki.
The game is a multi-scene story about an upstanding girl detective
who sexually dominates her boy partner, George."

Dlsite: http://www.dlsite.com/maniax/work/=/product_id/RJ123787.html

Getchu - http://www.getchu.com/soft.phtml?id=796716

DL Getchu - http://dl.getchu.com/index.php?action=gd&gcd=D0026548

Erogamescape - http://erogamescape.dyndns.org/~ap2/ero/toukei_kaiseki/game.php?game=19769

VNDB - https://vndb.org/v14615

DiGiket - http://www.digiket.com/work/show/_data/ID=ITM0093094/

Gyutto - http://gyutto.com/i/item117025

DMM - http://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_064501/

Melonbooks - https://www.melonbooks.co.jp/detail/detail.php?product_id=33499

Toranoana - https://www.toranoana.jp/mailorder/article/04/0030/18/10/040030181044.html

Pixiv - http://www.pixiv.net/member_illust.php?mode=medium&illust_id=40317392

Game OHP - http://rinrin.saiin.net/~yokubounotou/ss/onatan/

Artist - Aogiri Penta (あおぎりぺんた)

Base +37, date02 +6, Buraku-chan +10, elgringo +50, Before +12