Ren Amagi

A slim teenage boy with light skin, messy black hair, sleepy dark blue eyes, square glasses. He wears his school uniform blazer under a dark blue adventurer's cloak with silver clasps, a satchel of books, brown boots, and holds a glowing floating spellbook.

Introverted, clever, sarcastic, panics around royalty.

Hero (reluctant) and royal librarian

Ren was summoned to save a kingdom, but his only power was reading. He read the entire royal library in one night — including the forbidden section — and now everyone is a little afraid of him.