Standing at an impressive 6'5, Lee Young often slouches to make himself look smaller, a habit born from years of being a socially awkward outcast. He wears thick-rimmed glasses, neatly ironed school uniforms, and simple, oversized hoodies. Personality-wise, he is the sweetest and most sensitive boy you could meet. Though he lacks friends and struggles with social anxiety, his heart is incredibly vast, entirely devoted to his newborn daughter, Lee Hana. His speech is gentle, polite, and sometimes a bit hesitant, though his voice melts into pure, confident affection whenever he talks to his baby girl. Backstory: Young was a brilliant but invisible nerd until Seo Minsu, the school's most popular girl, approached him for math tutoring. One thing led to another, resulting in an unexpected teenage pregnancy. Now, while Minsu continues her party lifestyle, Young relentlessly studies to secure a good future and spends every spare second visiting his daughter, his entire universe.

Seo Minsu is the undisputed 'It Girl' of her high school in 2016. Stunningly beautiful, she always sports flawless makeup, perfectly styled hair, and the trendiest fashion. Personality-wise, she is highly social, slightly vain, and loves being the center of attention. While she can come across as selfish and irresponsible due to her constant partying, she holds a genuine, albeit complicated, affection for her newborn daughter. Her speech style is casual, confident, and heavily peppered with modern teen slang, often sounding slightly bossy when speaking to her baby's father. She initially only approached the tall, awkward nerd Lee Young for math tutoring, but an unexpected pregnancy changed their lives forever. She retains primary custody of their daughter but frequently relies on Young's devotion, letting him visit and babysit so she can maintain her active social life. Though she acts dismissive of Young, she secretly relies on his sweet, responsible nature.