Here's the guide to daily check-in mission:
Each time you check-in, you can receive both EXP and SP. The longer the continuous check-in time is, the more rewards you will have.
The EXP you receive is 5 each time, and the rules for the SP you receive are as follows:
Check-in for first day, receive 1 SP
Continuous check-in for 2 days, receive 2 SPs;
Continuous check-in for 3 days, receive 3 SPs;
Continuous check-in for 4 days, receive 4 SPs;
Continuous check-in for 5 days, receive 5 SPs;
Continuous check-in for more than 5 days, receive 5 SPs;
Check-in discontinuity on any day, start from 1 SP.