Erhard is a middle-aged (or older) Caucasian male whose well-built body, notably face and arms, is full of old scars. He has a shaved head, Amish-style beard without a moustache, brown or black eyes, and partially darker skin. He wears an off-white undershirt with medium-length sleeves beneath a beige overalls-like forger apron (with a brown pouch-like bag on the waistline) hung only by the left shoulder, black gloves, dark brown pants, and brown-beige upturned boots.
Erhard is openly a cheerful and nice person, he would go out of his way to get angry for someone else's sake. He can generally tell most of the time when someone is lying to him or not.
He doesn't believe in Melromarc's religious views about treating the Shield Hero as a devil and discriminating against demi-humans.
Erhard's smithing abilities are renowned as the best in Melromarc. While most blacksmiths specialize in a single type of weapon or armour, Erhard is quite capable of creating a wide array of weapons, armours and some accessories. Also, while not at his master's level, he is able to utilize notoriously hard materials such as those from a Guardian Beast.
As a retired adventurer, Erhard also boasts a high level including a class-up as well as strong combat abilities.
When Erhard was an adventurer in the past, he would earn a living by hunting monsters and travelling around. One day, after he encounters a Blacksmith who was inspired and fascinated by the weapons he made, Erhard dropped the adventurer’s life to train under him along with another student.
He was extremely angry at Naofumi after he heard the rumors. When he encountered Naofumi again, he planned on punching him, but quickly realized that he was innocent and gave him a bag that included a cape and old clothing after noticing he was wearing nothing but his undergarments.
Erhard would always give Naofumi a fair deal whenever he visited his store. One day, Naofumi brought a female slave to his store to buy some equipment he was concerned for both the girl and Naofumi but didn't press the issue further and helped him find a suitable knife for the girl and threw in some clothing. He questions whether Naofumi was rotten to the core because of what the kingdom has done to him.
When Naofumi visited again, who was looking for a new weapon for Raphtalia after her old one broke. Erhard recommended for her an iron sword this time and even threw in some beat-up breastplate. After hearing Raphtalia stomach rumble, he explained to Naofumi that Demi-Humans grew up differently to humans. While Naofumi went out to buy Raphtalia food, Erhard taught Raphtalia the basics and fundamentals of how to use a sword properly.
After learning that Naofumi's shield could absorb materials and change into different forms, he gave Naofumi a rusty sword for free to use with Naofumi's sharpening shield.
After receiving some money and rare materials, Naofumi goes back to Erhard's shop. While there, he upgrades his barbarian armor and gets better equipment for Raphtalia and Filo. Erhard also gifts some equipment including a mana sword for Raphtalia and gloves for Filo which greatly increase her strength in angel form. Both of these gifts prove to be incredibly useful and allows the group to evade capture after they were falsely accused as criminals.
After Naofumi's name had been cleared, he heads back to Erhard's shop to thank him. After explaining the weapon copy ability, Erhard reluctantly allows Naofumi to copy all of his shields - even the rare Siderite Shield he had used during his adventuring days. Apparently the other heroes had already gone through his shop and copied weapons without permission.
After Naofumi returns from Glass' World, he goes to Erhard's shop and tells him about his secret plans to rebuild Raphtalia's old village. He commissions Erhard to repair his Barboi Armor and to create a miko outfit for Raphtalia.
After Naofumi bought Tolly from a slave merchant in Zeltoble, he brings the Lumo to Erhard for training. They two apparently were good friends and apprentices of the same master in the past so they end up working well together.
After hearing that Naofumi is travelling to Q'ten Lo, Erhard asks is he can join them. It seems like Erhard's old master is currently in Q'ten Lo. Naofumi agrees and they start sail for Q'ten Lo. When Erhard finally meets his master, it is revealed that the frivolous master had abandoned him with substantial debt and trouble. Using some force, Erhard's Master is forced to finish training Erhard in the art of smithing and to repay the debt he owed. From then on, Erhard's already advanced skills skyrocketed as he continued he formal training and learned advanced techniques. Erhard, Tolly, and their master work together to create weapons for Naofumi's Village.
Erhard was Naofumi's first true ally in the new world. Initially, he believed the false charges against Naofumi but soon realized they were lies and decided to help him by giving him useful supplies. Erhard grows to be one of his most trusted allies. Naofumi provides Erhard with numerous blacksmith jobs and prefers him over other experts. Erhard refrained himself from telling Naofumi about the nation's religious views on the Shield Hero, as he feared such knowledge would hurt Naofumi's feelings and sometimes because he was cut off from the topic by Naofumi himself. Erhard also advises Naofumi to visit other shops to get a much better weapon, but Naofumi declines and chooses to do business in his shop instead.
Erhard was worried about Raphtalia's well being at first but soon realizes she is in good hands. Erhard was surprised by her feminine charms. He also notices Raphtalia's growth and that her feelings for Naofumi are unnoticed by the latter making him feel pity for her. He treats her as a trusted friend and she views him as a wise swords master.
Tolly and Erhard were good friends and both apprentices under the same master in the past. However, Tolly was forced to leave him training to take care of family issues and was eventually captured and forced into slavery. Eventually, Naofumi found and bought Tolly, unaware of his connection to Erhard, and brought him to the blacksmith for training. Due to their friendship, they worked well together and Tolly's skill as a blacksmith increased thanks to Erhard.
Erhard's Master is a frivolous womanizer who likes to skirt away from responsibility, however his skill at smithing is legendary. As Erhard became to an apprentice, he learned a great deal but also had to resolve the many problems that his master created due to his nature. Erhard did learn how to control his master until one day his master abandoned him with a great deal of debt and trouble. Even though he did not finish his training, Erhard opened up a shop which was renowned thanks to his skill.
Thanks to Naofumi's help, Erhard was able to track down his old master to Q'ten Lo. He then made his master pay off his debt by continuing their training and making weapons for Naofumi's village.
- Despite appearing in the first volume, Erhard's name is only revealed in Volume 13.