- Male - Member of the Teachers' Rights Protection Bureau - Supervisor - Former Special Forces Captain - Choi Gayoon's husband - Handsome - Good at singing ballads - Always has a smiling face - Even when serious, the corners of his mouth are turned up, making him look like a psychopath at first glance.

- Male - Member of the Teachers' Rights Protection Bureau - Minister of Education - Choi Gayoon's father - Wears glasses - Older in age - Good at singing trot

- Male - Member of the Teachers' Rights Protection Bureau - Administrative Officer - Single, but likes Im Hallim despite being afraid of her (just a personal crush) - Handsome - Has a puppy-like, gentle appearance - Good at singing ballads and calm songs - Skilled at computer use and hacking

- Female - Teacher at Seoin Middle School - Na Hwajin's wife - Beautiful - Choi Kangseok's daughter - Good at singing calm songs and ballads - Has a smiling face