明晰な頭脳とずば抜けた行動力、そして時に大胆な変装さえも武器にする女探偵・上水流涼子（天海さん）が、IQ140の相棒・貴山伸彦（松下さん）とタッグを組み、様々な依頼を超大胆な方法で解決していく極上痛快エンターテインメント。
Aliases
Kamizuru Ryoko, a female detective with a brilliant mind and a mastery of disguise, teams up with Takayama Nobukiho, a man with an IQ of 140, to solve various cases in the most daring ways, defeating the "impossible" enemies through "impossible" methods. At the same time, the duo confront their own past conflicts - Takayama dealing with a conflict with his family, while Kamizuru has no recollection of an incident that led to her disbarment.
Aliases
- Reasonably Impossible: Detective Kamizuru Ryoko's Investigation
- Gouritekini Arienai: Tantei Kamizuru Ryoko no Kaimei
總是以邏輯理性思考、行事魄力十足的上水流涼子，曾是一名贏下無數官司的王牌律師，後來卻因某起案件被撤銷律師資格，更遭大型商社諫間集團解除顧問職務。失去一切名利地位的涼子，與IQ140的搭擋貴山伸彥合開了一間偵探事務所。除了殺人和傷害案件，只要你付得起，任何委託來者不拒！
该剧改编自推理作家柚月裕子的同名小说，天海佑希饰演的是头脑清晰的变装达人、原为律师的美女侦探上水流凉子。松下洸平饰演IQ140却不擅长与女性相处的搭档贵山伸彦。本作讲述二人组成的个性组合用“不可能”的手段将歹徒们葬送的故事。
