Thriller dramas with a investigation team

Need recommendations on Thriller dramas with a investigation team. Prefer Kdramas and Jdramas.

Honestly I think some of the best team thriller dramas are found in Chinese/Taiwanese productions. I know you mentioned you only want Japanese or korean but Id highly recommend you to give Burning Ice and  Trinity of Shadows a try. These 2 are damn amazing.

Otherwise:
Watcher
 Signal
The Good detective 
Stranger
Special Affair Team Ten
38 Task Force 


Japanese:
Sushi no Kodo (all parts of this one)

• Taxi Driver
• 38 task force
• Player
• Lookout
• Leverage
• Voice
• Tunnel
• Lucky seven
• 99.9 criminal lawyer
• Tantei kizoku
• Kagi no kakatta Heya
• The confidence jp man
• Mad dog
• Signal
• Sketch