Proceed With Caution

Go Jae-Hyuk, once a promising kendo athlete, has gone off the right path and gotten involved with the wrong crowd. But Han Yeong-Won, a Sergeant at the Daehan Police Station, used to keep him in line. The two men are completely different in every little way, but they meet again and rekindle their friendship thanks to the only thing they have in common: their children. Jae-Hyuk, a complete noob at parenting, moves in with Yeong-Won, starts learning little by little, and begins to recognize his own traits as a dominant alpha. Two grown men, each with his own wounds, children, and confusing, tangled feelings for each other, become an unlikely family as their lives intertwine in a completely new way.
(Source: Bomtoon, translated)