Naofumi is Shield the Hero and is a 20-year-old otaku university student. After reading the ‘Book of the Four Holy Weapons’ he was summoned to another world. He has tremendous defense powers, but he has, more or less, no attack power. In the new world, he becomes a misanthrope and his original gentle personality disappears and he becomes a cold individual.

Raphtalia is the first demi-human slave that Naofumi bought in the new world. She is of the racoon variety and has a direct personality. She accompanies him everywhere and acts as his sword.

Filo is a demon with bird-like wings and is called Filolial. She is the Filolial Queen and has an advanced-level of shapeshifting. She often takes the form of a girl with wings. she excels at wind magic and is a bright, upbeat girl who loves to eat.

Ren is Sword the Hero and is a 16-year-old high school student. He’s short in stature, but is a beautiful young man with handsome features. He’s an intellectual and proud, and this means that he has a propensity to look down on others.

Motoyasu is Spear the Hero and a 21-year-old university student. He’s used to dealing with women and his parties consist of women only. When he is surrounded by women, he loses sight of his surroundings, and he is easily tricked.

Itsuki is Bow the Hero and a 17-year-old high school student. He has a gentle disposition but is somewhat fickle. He is the shortest among all of the heroes, but he has a stronger sense of justice than anyone else. When he is on the path to establishing justice, he tends to lose sight of things around him.

Lithia is from the north of Melromarc. Her family was once a noble one, but has since lost its glory. She was nearly sold due to corrupt nobles, but thanks to Itsuki’s world reformation she was saved and instead became his comrade. However, due to her involvement in the Cal Mira Archipelago wave, Itsuki and his friends get the wrong idea and banish her from the group. After that she joins up with Naofumi.

Melty is a girl who Filo met. She is a bit serious and places her friends first, but when she does get emotional sometimes, her child-like side comes out. And for some reason, she has some sort of secret...

Mireria is the most powerful character and the queen of Melromarc. While Mireria was out on a diplomatic errand with her daughter Melty, Aultcray and the three heroes’ caused her to lose the right to summon the four heroes. However, after long disputes with Faubrey - the kingdom that holds the real power to summon the heroes - as well as many other countries, she finally managed to get the rights to summon the four heroes again. She has high hopes for her daughter Melty, next in line to become queen.