Investigation and inspection with

means “to investigate” or “to clarify”. It is used when examining something in detail to uncover the truth or when verifying whether something is correct or incorrect by comparing it to a standard.

Etymology

This kanji is a phono-semantic compound comprised of 木 (wood) as the semantic component and 且 as the phonetic component, giving the on-reading サ. It originally referred to a wooden raft, before making a semantic shift from checking a constructed object piece by piece to examining things carefully.

Evaluations

(Inspection)

検査(けんさ) means an inspection, examination, or test for defects, suitability, or health problems.

It combines 検 (check) with 査 (inspect) to show a close inspection.

Manga panel from からかい上手の高木さん showing example of Classroom bag inspection with 検査.
からかい上手の高木さん » Volume 11 » Page 22

Nishikata and Takagi are on duty preparing the classroom before class.

高木(たかぎ):
「そういえば今日(きょう)()ちもの検査(けんさ)があったような気が…」
“Come to think of it, I think we have a bag inspection today…”
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Investigations

(Investigation)

調査(ちょうさ) means an investigation, survey, or detailed examination of the facts.

It combines 調 (examine) with 査 (investigate) to show a careful investigation.

Manga panel from 名探偵コナン showing example of A discreet investigation with 極秘.
名探偵コナン » Volume 1 » Page 129

Detective Mouri’s favorite idol, Yoko, comes to his agency after receiving threatening calls and candid photos. Her manager hopes to keep the matter quiet to protect her image.

毛利(もうり):
承知(しょうち)しました!極秘(ごくひ)調査(ちょうさ)するとしましょう!!」
“Got it! Let's investigate this discreetly!!”
ヨーコ:
「あ、ありがとうございます!!」
“Thank you very much!!”
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(Investigation)

捜査(そうさ) means a criminal investigation by police or prosecutors to identify suspects and gather evidence.

It combines 捜 (search) with 査 (investigate) to show a thorough search and investigation.

Manga panel from 名探偵コナン showing example of Helpful invention for an investigation with 捜査.
名探偵コナン » Volume 1 » Page 122

Conan is now staying with Detective Mouri in hopes of finding a case related to the men responsible for his becoming a child. He stops by Professor Agasa’s place to discuss the situation.

阿笠(あがさ):
「おお、そうじゃ!!」
“Oh, that's right!!”
(きみ)捜査(そうさ)(やく)にたつと(おも)って、(つく)った(もの)を…」
“I made this thinking it might help with your investigation...”
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