[talk] I was curious about what kind of group Cypher was, so I looked it up.

I think this is an idol created by singer Rain.

'Ciipher' means 'those who have a password'.

It means, 'I will be friendly off stage, but I will show a strong side with a secret code on stage.'
It seems like the members have a chant that goes something like, "Can't sleep? No! You have to be cool! Let's go!"
It looks like a 3-member group excluding the members who left.