While most ONCEs already know about this adorable TWICE tradition, newer fans may not know about it or why it exists in the first place.
During a previous appearance on JTBC‘s Knowing Bros, Chaeyoung revealed the group’s secret.
Although comedian Kang Ho Dong guessed what the secret was, it was Chaeyoung who confirmed it.
As for how the tradition started? Well, a fan asked Tzuyu what she wanted for her birthday…
… And she said she wanted kisses from the other members!
Goodness, why are the members of TWICE so wholesome and cute?