Lehman

Fish-san (リーマン) is a human-faced fish monster that is constantly traveling.

Appearance
Lehman has an appearance of a fish, however his unusual appearance is his head which looks like that of an old man.

Personality
Lehman has a grumpy personality, analogous to that of an old man's, but he is actually very friendly and humble with Hajime Nagumo, and really appreciates Hajime's help when he rescued him from captivity in Fuhren. Another proof of his gratitude is when he stalls the monster near the Sunken Ruins of Melusine that attacks Hajime and his companions.

Lehman loves to travel and explore the world. He can't stand to be in one place for too long, which usually puts him at odds with his wife since she wishes for him to spend more time with her and their children.

Chronology
Lehman was swimming in a river not too far from Brooke Town, when it suddenly erupted due to Hajime Nagumo and his companions getting flushed away from the Great Reisen Labyrinth by Miledi Reisen. The only one who spotted Lehman was Shea Haulia. Lehman looked at her and asked what she was looking at using Telepathy. This shocked Shea and nearly caused her to drown after she inhaled some water.

The rupture in the lake caused Lehman to be ejected onto dry land, where he was found by some humans and taken to the Meerstadt Aquarium in Fuhren. During his captivity, Lehman would once again meet up with Shea while she was on a date with Hajime, and was surprised to see the strange fish again. She then began to stare at it intensely, but this soon caught Hajime's attention, and prompted him to speak with Lehman using his own Telepathy after reading that his species had that ability from the plaque on his tank. Lehman was surprised that Hajime could use the same special magic as him since it was a skill that was normally used by Monsters. The two of them got into a long telepathic conversation before Shea intervened. Hajime decided to free Lehman by using one of his "Cross Bit" artifacts after he and Shea left the aquarium.

Lehman would meet up with Hajime again, along with the rest of his party, outside of the Sunken Ruins of Melusine. They were fighting an ancient gelatinous aquatic monster called a devourer and Lehman could sense a large gathering of mana from the battle. Lehman used his Telepathy to control a school of fish as he prepared for battle. Upon their reunion, Hajime asked Lehman to distract the monster for three minutes, to which he obliged him. Though the devourer eliminated all of Lehman's fish, he was still able to buy Hajime enough time for him to craft the weapons he would need to win. The end result caused a massive explosion that vaporized the devourer, and also cause Lehman to be caught in the aftershock. Lehman berated Hajime for using such excessive means without warning him beforehand, to which Hajime apologized. The two of them then shared a heartfelt moment over their reunion, which surprised Hajime's female companions. Ash Lehman was about to take off, he approached Shea and rooted for her in her efforts to win over Hajime, and even vowed to introduce his own family to them one day if the two of them ever had kids. Hajime and his companions were utterly shocked to learn that Lehman was married.

Some time later, Lehman encountered the young dagon Myu out in the ocean, after sensing the magic from a pendent she wore that Hajime gave her, which among its various abilities, gave Myu the power of "Telepathy". At first, Myu was scared of Lehman, but quickly calmed down after he convinced her that he was harmless. Upon learning that Myu was Hajime's adopted daughter when he inquired her about her pendent, Lehman vowed to help her if she was ever in trouble, and also giving her advice on the type of wife that Hajime should be with (with him explicitly warning against marring someone who was domineering). Just then, Lehman's wife appeared and dragged him down to the bottom of the ocean while complaining to him about not spending enough time with her or his children.

Hajime Nagumo
Lehman is considered to be Hajime's first male friend since he was summoned to Tortus. The two of them instantly bond when they first meet at the aquarium in Fuhren where Lehman was being held.

Shea Haulia
Shea is scared of Lehman during her first encounter with him, but she is later grateful to him since the shock of their meeting inadvertently lead to Shea's first kiss with Hajime.

Myu
Lehman vows to help Myu when in need after discovering that she is Hajime's daughter.

Remia
Remia does not like Lehman due to him filling Myu's head with misconceptions about the type of wife that Hajime should be with.

Inaba
The two of them are good friends. Inaba greatly respects Lehman due to him having Hajime as his benefactor.

Physical Abilities

 * ''Expert Swimmer - As a sea-based monster, Lehman is much faster in the water than most land-based beings.

Magical Abilites

 * Ichthyoid Manipulation - Thanks to his telepathic powers, Lehman can magically control fish.

Skills

 * Mana Manipulation - It allows direct manipulation of mana without the need for magic circles or incantations.
 * Telepathy - It allows the user to communicate with people by transference of thoughts in their mind within a certain range.
 * Detect Magic - It allows the user to detect and perceive the flow of mana and activation of hidden or ranged spells and magic.

Weapons & Equipment

 * Treasure Trove Scales - Lehman's scales are remolded by Hajime so that they can act like personalized Treasure Troves. They contain many artifacts that Hajime has given him.
 * Triana v.2 - A small submarine that can be used for underwater, as well as flight. The cockpit is full of water and is controlled by Lehman's "Telepathy". Its propulsion system is based on Hajime's design for a perpetual energy system that he devised after his encounter with the Sky Dragon World. Like most of Hajime's vehicles, it's outfitted with many weapons.

Quotes

 * (To Hajime): "My dear boy, what kind of creatures are humans? If I asked you that right now would you be able to answer? You wouldn’t, right? All I can say is I’m me. Nothing more, nothing less. I can’t say I have a name either, so just address me however you wish."

Trivia

 * Lehman's appearance in the Light Novel and Manga is similar to the fish from the video game .
 * In the Anime, Lehman does not use his Telepathy to speak with others, and instead talks to them normally.