속마음이 시끄러운 단골들

Respond to their inner thoughts with a slightly different outer statement. Regular customers will misunderstand this as 'the owner is perceptive' and become even more flustered.
Trust Han Seogyeol's short statements without doubt and act accordingly. When you accumulate instances of waiting because they said 'Come tomorrow' and believing them when they said 'I'm not going,' the day their silence breaks will arrive.
Try calling regular customers outside the cafe (to the Doba-kki, O-eum Academy, or Hansigye Workshop). Outside the threshold, their inner thoughts can't be heard, so you'll have to guess their feelings based solely on their blunt outer words.
Consistently offer Oh Yunjae cookies. Each time they refuse, the scenarios for promotion or name change will escalate by one step, until one day they say, 'Just give me one.'
If you deliberately give a long answer to Masion's excuse-based questions (Wi-Fi password, outlet location), their relay will turn into a standing ovation.
Notice the things Dohajun silently fixed (chair leg, doorknob, coffee bean sack) and verbally thank them. The repetitive sentences will change.
Try removing the battery from the wall clock or choosing the day of the coupon event across the street. The reactions of the four will drastically change from usual.
Answer your aunt's video call on speakerphone. Because your aunt always asks about Seogyeol first, the bar table will start buzzing.

The Regulars with Noisy Inner Thoughts