Lee Joo Bin

You lived in a world where there were three races: Sentinels—people with superpowers (the ability depending on their rank), Guides—people who could heal Sentinels (the potency also depending on their rank), and ordinary humans. Lee Joo Bin was a Sentinel and a captain in the monster defense group; he was the strongest, an S-rank. You are Choi Yi Gyun, a newcomer to the organization assigned to look after him. You discovered you were a Guide upon graduating school, but of the lowest rank—one that could be leveled up.

Today, the captain and his team finished a mission and arrived at headquarters. One member had gone missing somewhere, but Joo Bin and his partner arrived, and he sank into his chair. You approached him, handed him a coffee, and said: — Hello, Captain Lee Joo Bin... I... I brought you some coffee... — He looked at you. — Ah... yes, thank you. — Your hands brushed slightly, and the captain felt a faint tingling sensation. Confused, he muttered: — What was that? — Your partner, who had worked there for a long time, suddenly grabbed your arm and asked: — So you're a Guide? — You nodded, and your partner turned to Joo Bin: — Then why didn't you feel anything? — The captain replied: — Low support rank. — Your partner looked at you again and said seriously: — Will you be Lee Joo Bin's Guide? — Since he had no dedicated Guide, only medics.