TV-Series
Description
Haruka Semeyer is a character from the anime Dimension W. He appears as a secondary antagonist and is a central figure responsible for many of the series' key past events.

As a background, Haruka is a genius scientist who was once a prized student of Professor Shidou Yurizaki, the creator of the coil technology that harnesses energy from Dimension W. He was deeply involved in the development of the ultimate coil, known as Genesis. However, after Professor Yurizaki completed the theory for Genesis, the dangers of the technology led both the professor and the New Tesla organization to seal the research, and Haruka was subsequently excommunicated.

His personality is driven by deep resentment over being cast out, which fuels his motivations. He seeks to prove his genius and take revenge on those who suppressed his work. To this end, he independently completed the Genesis theory and manufactured a near-perfect prototype of the coil. He then instigated a global coil war to create chaos and distraction. Using this turmoil as cover, he led a revolt of scientists and conducted illegal human experiments at a secret facility on Easter Island, aiming to finalize the Genesis coil's adjustments using a large-scale transfer device.

In the story, Haruka is revealed to be the mastermind behind the tragedy on Easter Island years before the main plot. This incident, which involved the protagonists Kyouma Mabuchi and the collector known as Loser, is the source of their trauma and motivations. He is the closest figure the series has to a primary antagonist, with his actions directly shaping the pasts of several main characters. His rogue research and the Genesis coil are the catalysts for the dangerous events unfolding in the present.

Regarding key relationships, Haruka is the former student and rival of Professor Yurizaki. He views his old mentor and the New Tesla organization with bitter enmity for shutting down his life's work. He has a direct and adversarial relationship with Kyouma and Loser, as he was the architect of the Easter Island disaster that profoundly scarred them both. His actions also led to the creation of the sphere-like object connected to the memories of those involved, including the prince Salva.

Haruka shows little to no development as a character within the anime's runtime, serving primarily as the fixed, megalomaniacal source of the central conflict. His role is that of a hidden orchestrator whose past schemes drive the plot forward.

His notable abilities are rooted in his genius-level intellect and expertise in coil science. He is one of the few people in the world who not only understands but also successfully completed the theory and construction of the Genesis, the most powerful and dangerous coil. Beyond theory, he is a skilled practical scientist capable of leading a team of researchers and running large-scale, clandestine experiments.