Character mistake: The invitation for the wedding comes with a calendar for the month of April, with the date of the wedding circled. There are 31 days shown on the calendar, but there are only 30 days in April. (01:12:42)
Episode #1.3 - S1-E3
Continuity mistake: When talking about relationships in the coffee shop, Jin-a asks "But what if we keep missing the right time" and her friend is shown with a drink on the table. The straw inside the drink is shown at a tilted angle when Jin-a says this, but when it cuts to the friend, the straw is suddenly at an upright angle. (01:15:08)