Saya mau tau Pemeran dari 7th Grade Civil Servant

Choi Kang-hee - Kim Seo-won / Kim Kyung-ja

Joo Won - Han Gil-ro / Han Pil-hoon

Hwang Chansung - Gong Do-ha

Kim Min-seo - Shin Sun-mi

Ahn Nae-sang - Kim Won-seok

Jang Young-nam - Jang Young-soon

Im Yoon-ho - JJ / Choi Woo-jin

Dokgo Young-jae - Han Joo-man, ayah Gil-ro

Im Ye-jin - Go Soo-ja, ibu Gil-ro

Lee Han-wi - Kim Pan-seok, ayah Seo-won

Kim Mi-kyung - Oh Mak-nae, ibu Seo-won

Noh Young-hak - Kim Min-ho, adik laki-laki Seo-won

Choi Jong-hwan - Oh Kwang-jae, direktur NIS

Son Jin-young - Kim Poong-eon

Lee El - Park Soo-young

Jung In-gi - Kim Sung-joon

Seo Seung-man - manajer IT&TI

Lee Hye-eun - istri Won-seok

Chu Ye-jin - Kim Seo-won muda

Uhm Tae-woong - Choi Woo-hyuk (penampilan tamu, ep 1-4)