Arthur Richter, also referred to in some sources as Artur Lichter, is a supporting character in the anime and light novel series. His background is rooted in nobility and religious authority, as he is the son of a count and comes from a long line of prominent priests. This heritage positions him as an up-and-coming mage of significant standing, to the point that he is entrusted with government assignments even while still attending school. He is also a knight in training, indicating a dual path of both martial and magical prowess.

In terms of personality, Arthur is portrayed as a pragmatic and logical individual. His actions are typically driven by rationality and a focus on achieving results efficiently, which can sometimes lead others to perceive him as cold, aloof, or difficult to approach. Compared to his childhood friend, Crown Prince Siegwald, Arthur is noted to have a slightly more morally ambiguous nature, suggesting a willingness to operate in gray areas that the prince might avoid. Despite this exterior, he possesses high moral standards and is known to speak out against injustices he witnesses within the kingdom. Beneath his reserved demeanor, he is also a caring person who grows more emotionally open as the story progresses.

Arthur’s primary motivation is the protection of the royal family and the kingdom itself. As a loyal servant to the crown, his sense of duty is paramount. This is complicated by his relationship with the protagonist of the game within the story, a commoner girl named Fiene. In the original otome game's narrative, Arthur has a crush on Fiene, and his tragic fate is to die protecting her in all but three of the possible endings. This predetermined death makes him a target for the real-world commentators, Endo and Kobayashi, who seek to avert the game's tragic outcomes.

Within the story, Arthur serves as a crucial supporting character in the royal court. He is one of the few people with whom the Crown Prince Siegwald can be genuinely intimate and vulnerable, a consequence of the isolating nature of monarchical responsibility. This makes Arthur’s role as a confidant vital to the prince’s well-being. He also has a connection to the villainess, Lieselotte, as one of the two people the prince can be close to. His key relationships include his childhood friendship with Siegwald, his unrequited affections for Fiene, and his loyalty to the royal family. His dynamic with the other characters evolves as the timeline changes, allowing him to potentially avoid his canonical death.

Arthur undergoes significant character development throughout the series. Initially reserved and defined by his logical and dutiful nature, his interactions with the cast and the ripple effects of Endo and Kobayashi’s commentary lead him to lower his emotional barriers. He begins to open up more to those around him, revealing a more vulnerable and caring side than he typically displays. This growth allows him to form deeper connections and move beyond the rigid, tragic path set for him in the original game.

Regarding notable abilities, Arthur is a highly skilled mage, with his priestly lineage granting him considerable magical talent. He is also a capable knight-in-training, proficient in combat. His strategic mind and analytical thinking make him a natural leader and a valuable asset in planning and execution, as he prefers data-driven solutions to problems. These abilities, combined with his government experience, mark him as a formidable and multifaceted asset to the kingdom.