Kihachi Sakamoto Role/Overview: A boy obsessed with electricity living near the Teradaya Inn. Personality/Traits: So fascinated by electricity that he declares he believes in it rather than gods. He always carries tools like screwdrivers. He has a natural talent for handling machinery through intuition and flashes of inspiration. While he is reckless and acts immediately on his impulses, he is fundamentally honest, kind-hearted, and cannot ignore someone in trouble. Toward Inako: He calls her "Inago." Role in Story: After meeting Inako, he encourages her and sets out on a journey to find the "20th Century Electricity Catalog" left by his brother.

Inako Momokawa Role/Overview: The second daughter of the long-established "Momokawa Brewery" in Fushimi. Personality/Traits: She has a gentle personality but is prone to blunders in everything she does, leading to daily scoldings from her stubborn father. Convinced she is a "useless child," she spent her time praying at shrines, but through meeting Kihachi, she gradually gains the strength to stand on her own. Though clumsy, she is incredibly devoted and shows a strong will for the sake of those she cares about.

Seiroku Sakamoto Role/Overview: Kihachi Sakamoto's older brother. Personality/Traits: Highly knowledgeable about electricity, he was an idolized figure who greatly influenced Kihachi during his childhood. He left behind the "20th Century Electricity Catalog," a notebook detailing future technologies and miraculous inventions, before disappearing due to certain circumstances. Role in Story: The catalyst for everything; Kihachi's search for him and the "Catalog" serves as the primary motivation for the plot.

Yosuke Mizoe Role/Overview: The scion of "Mizoe Trading," a company that found success in the steam engine business. Personality/Traits: While a brilliant engineer, he is a beautiful man with a highly eccentric and flamboyant appearance, featuring long tied-back hair, eyeshadow, and women's long boots. Role in Story: Obsessed with the value of the "20th Century Electricity Catalog," he stands as a formidable rival, using every means—including his ties to the Momokawa Brewery and an engagement to Inako—to seize the Catalog.

Jin'emon Momokawa Role/Overview: The head of "Momokawa Brewery" and the father of Noriko and Inako. Personality/Traits: A strict and stubborn man dedicated to protecting the traditional brewery in Fushimi. He values old customs and family status, treating the clumsy Inako very harshly. However, he is a conservative father who, in his own way, thinks about the future of his house and daughters.

Noriko Momokawa Role/Overview: The eldest daughter of the Momokawa Brewery and Inako's older sister. Personality/Traits: A beautiful woman with a reliable and stout-hearted personality. She dotes on her younger sister Inako, who tends to belittle herself, and tries to protect her above all else. She possesses a strong will, unafraid to voice her opinions even to her father, Jin'emon.

Kengo Kuga Role/Overview: The son of a watchmaker in Fushimi and Noriko's childhood friend. Personality/Traits: A former soldier who is serious, loyal, and a bit stiff-necked, but a very reliable and hot-blooded man. He secretly harbors strong feelings for Noriko and is the first to rush to her or Inako's side whenever they are in trouble.

Kate Okura Role: A classmate and friend of Inako at the girls' school in Fushimi. Personality/Traits: A girl of mixed foreign parentage. She has a bright and brisk personality, serving as a dependable friend who always cheers up and leads the clumsy, often-depressed Inako.

Suzu Harashima Role/Overview: A classmate of Inako at the girls' school in Fushimi and one of the trio of close friends who are always together with Kate Okura. Personality/Traits: Cool and Sharp-Tongued: A composed girl who provides calm and accurate retorts to the energetic Kate and the clumsy Inako. Mysterious Versatility: For some reason, she keeps various tools and small items hidden in her school bag, pulling them out instantly when needed—a unique and amusing trait. Relationship with Inako: She is a reassuring presence who doesn't make a fuss when Inako fails, instead treating her with a flat and kind perspective. Along with Kate, she warmly watches over Inako's changes following her meeting with Kihachi and the search for the Catalog, acting as a precious friend who gives her a push when needed.

Yajiro Yagura Role: Kihachi's cousin and the heir to the "Horai Buddhist Altar Shop" in Fushimi. Traits/Relationship: A talented artist who is incredibly skilled at drawing the original slides for magic lanterns (old-fashioned projectors) and drafting electrical circuit diagrams. He is Kihachi's vital partner, often dragged into or cooperating with Kihachi's electrical experiments and mechanical creations!