Live action TV
Description
Mika Natsume is the daughter of Professor Natsume, a researcher who discovered the original Kuuga Arcle and was killed by the Gurongi monster Daguva. Years after the main events of the series, she uncovers her father’s notes, which detail the existence of a prototype Arcle created before the one used by Yusuke Godai. This prototype is incomplete, lacking the Amadam stabilizing stone, and drove its previous user insane. Driven by grief, a desire for justice, and the lingering threat of remaining Gurongi, Mika impulsively seeks out the prototype and bonds it to her body, gaining the ability to transform into a new, flawed version of Kuuga.

Mika is initially portrayed as a young woman in her late teens or early twenties, originally from Kyoto, who moved to Tokyo with the ambition of becoming an actress. She stays at a coffee shop called Pore Pore and helps out there while pursuing her dream. Her father’s murder left her deeply depressed and feeling that his death was overlooked because of the larger Gurongi attacks. This unresolved grief fuels a strong need for vengeance and a personal mission to eliminate any remaining Gurongi. She is headstrong and impulsive, often acting before fully considering the consequences, which leads her to take on the prototype Arcle without understanding the risks.

Her personality matures as she confronts the instability of her power. She struggles with the fear of losing control and harming innocents, a fear that manifests in nightmares of herself going berserk. Despite this, she is determined to train and prepare, teaching herself basic martial arts by watching videos and studying how the original Kuuga fought. She is resourceful and resilient, but also isolated, as she hides her transformation from authorities and even from those who might help her, such as police detective Kaoru Ichijou. Her primary motivation shifts from pure vengeance to a more complex desire to master her power and prove that she can be a protector rather than a danger.

In the story, Mika serves as a new and unstable Kuuga, operating in the shadows about twelve years after Yusuke Godai’s final battle. She inadvertently draws the attention of Ichijou, who investigates sightings of a white warrior similar to Kuuga. Her role is that of a successor who must confront not only external enemies but also the internal threat of her own transformation. She engages several Gurongi, using her growing combat abilities and a unique weapon that manifests as a cannon rather than the sword or rod used by the original Kuuga. Her most dangerous form is a black variant that appears when she gives in to rage, causing her eyes to flicker red and black before going fully dark as she loses control.

Key relationships include her deceased father, whose memory and research set her on this path. She holds deep respect and admiration for Yusuke Godai, the original Kuuga, and dreads the possibility of having to fight him. Godai eventually intervenes, using his own Rider powers and machines to stop her from descending into madness. Kaoru Ichijou, the detective, is another important figure; he suspects her secret but remains a supportive if cautious presence, and their past friendship allows for tense but meaningful interactions. Through these connections, Mika develops from a solitary avenger into someone who recognizes the need for help and guidance.

Her notable abilities stem from the prototype Arcle fused to her spine. She can transform into two forms: a white form similar to Kuuga’s Growing Form, and a black form that resembles the Ultimate Form but carries the risk of complete loss of control. Unlike the original Kuuga, her weapon manifestations are different; she can turn objects into cannons capable of firing energy blasts. She also possesses superhuman physical attributes, including strength, speed, and jumping ability, though her inexperience and the incomplete nature of her power make her weaker and more unstable than the original Kuuga. Her greatest challenge is not the Gurongi she fights but the madness that threatens to consume her each time she transforms. Her story arc culminates in a confrontation with Godai, who stops her rampage and helps her find a measure of peace, though the Arcle remains a permanent part of her, leaving her future uncertain.