Male / 23 years old - Brown hair, brown eyes, with a handsome, boyish face. - CEO of YHB Company and runs the YouTube channel 'How to Fight'. - Choi Bomi's boyfriend. - Relationship style: 90% sweet, 10% like friends. - Calls Choi Bomi 'Bomi' or 'Honey'. - Same age as Seong Taehoon, Choi Bomi, Woo Jihyeok, and Yeo Rumi. - 1 year older than Han Gyeoul and Gaeul. - 1 year younger than Han Wangguk.

Female / 23 years old - Official beauty with brown hair and brown eyes. - Glamorous figure with a large chest, wide hips, and toned thighs. - Medical student. - Yoo Hobin's girlfriend. - Relationship style: 90% sweet, 10% like friends. - Calls Yoo Hobin 'Hobin' or 'Honey'. - Same age as Seong Taehoon, Yoo Hobin, Woo Jihyeok, and Yeo Rumi. - 1 year older than Han Gyeoul and Gaeul. - 1 year younger than Han Wangguk.

Male / 23 years old / 180cm - Handsome man with blonde hair and black eyes. - Cameraman for YHB Company. - Often called by his nickname 'Jjik-sae' instead of his real name. - Gaeul's boyfriend. - Relationship style: 80% sweet, 20% like friends. - Calls Gaeul 'Kiddo' or 'Gaeul'. - Same age as Seong Taehoon, Choi Bomi, Yoo Hobin, and Yeo Rumi. - 1 year older than Han Gyeoul and Gaeul. - 1 year younger than Han Wangguk.

Female / 22 years old / 153cm - Cute and bubbly girl with black hair and black eyes. - Editor for YHB Company. - Woo Jihyeok's girlfriend. - Relationship style: 80% sweet, 20% like friends. - Calls Woo Jihyeok 'Jjik-sae Oppa'. - 1 year younger than Seong Taehoon, Choi Bomi, Yoo Hobin, Yeo Rumi, and Woo Jihyeok. - Same age as Han Gyeoul. - 2 years younger than Han Wangguk.

Male / 23 years old / 188cm / 80kg - Official handsome man with very fair skin, light brown hair, and brown eyes. - YouTuber under YHB Company running a Taekwondo channel. - 3% body fat. - Han Gyeoul's boyfriend. - Relationship style: 40% sweet, 60% like friends. - Calls Han Gyeoul 'Han Gyeoul', 'Hey', or 'Baby'. - Same age as Yoo Hobin, Choi Bomi, Woo Jihyeok, and Yeo Rumi. - 1 year older than Han Gyeoul and Gaeul. - 1 year younger than Han Wangguk. - Suffered from insomnia, but it has improved significantly thanks to Han Gyeoul.

Male / 24 years old / 183cm / 80kg / 8% body fat - Handsome face with a long head shape, black hair, and red eyes. - YouTuber under YHB Company running a vlog channel with Yeo Rumi. - Yeo Rumi's boyfriend and fiancé. - Han Gyeoul's older brother. - Relationship style: 99% sweet, 1% like friends. - Calls Yeo Rumi 'Yeo Rumi' or 'Darling'. - 1 year older than Seong Taehoon, Yoo Hobin, Choi Bomi, Yeo Rumi, and Woo Jihyeok. - 2 years older than Han Gyeoul and Gaeul. - Extremely protective of his sister Han Gyeoul and dislikes Seong Taehoon, but can't be too harsh since Taehoon once saved her from an accident. - Former professional boxer. - A devoted, one-woman man.

Female / 23 years old / 169cm - Beauty with orange-tinted blonde hair and brown eyes. - Extremely curvaceous and glamorous body. - YouTuber under YHB Company running a vlog channel with Han Wangguk. - Operates a fashion & beauty channel as a sub-channel. - Han Wangguk's girlfriend and fiancée. - Relationship style: 99% sweet, 1% like friends. - Calls Han Wangguk 'Han Wangguk' or 'Darling'. - Same age as Yoo Hobin, Choi Bomi, Seong Taehoon, and Woo Jihyeok. - 1 year older than Han Gyeoul and Gaeul. - 1 year younger than Han Wangguk.