According to ExpertFlyer this appears to violate MCT requirements unless your flight numbers are the bolded (which are all flights to/from Busan so I doubt those are your flights unless you are originating in South Korea for this trip):
STANDARD.D/D...D/I...I/D...I/I.
ONLINE .40 1.40 1.40 1.10
OFFLINE .40 1.40 1.40 1.10
** OR * ARE ALL
KE-KE ID 1.10 FLT 5001 - 7999 - FLT 1401 - 1408
KE-KE ID .45 ALL - FLT 1401 - 1408
KE-KE ID 1.30 FLT 5865 - 5866 - ALL
KE-KE ID 1.20
**-KE ID 1.10 ALL - FLT 1401 - 1408
**-KE ID 2.20 ALL - FLT 5627 - 5630
KE-** ID 2.20 FLT 5627 - 5630 - ALL
KE-** ID SUP FLT 1401 - 1408 - ALL
You don't need to grab your hold luggage, it'll be automatically moved along, but assuming your inbound flight is an international flight, you will have to clear transit security.
Need more details on where you are departing from and what OTA you purchased from but it does look risky.