TV-Series
Description
Birthday operates as a carefree handyman in Yokohama, frequently diving into money-making schemes. He sports blond hair with distinctive pink shading and blue eyes, usually hidden behind his signature sunglasses. His typical attire consists of a yellow shirt, a dark red tracksuit (later switched to black), sandals, and a black skull tattoo adorning his right lower leg.

He maintains a consistently jovial and laid-back personality, creating a stark contrast to his partner Ratio. Birthday often exhibits lewd behavior, particularly directed at the uninterested Honey. Despite this playful exterior, he possesses deep loyalty towards friends and expresses strong contempt for quitting or sulking. Afflicted by an incurable illness since childhood, Birthday consciously chooses an energetic life, refusing to let his condition diminish his outlook.

His backstory reveals a long-standing bond with Ratio, forged in their youth when Ratio predicted Birthday's imminent death. Birthday challenged this by betting his survival from critical surgery would destroy Ratio's "Prophet of Death" persona. His miraculous survival led him to declare he had "killed" Ratio's former self, enabling Ratio's rebirth and cementing their partnership. Birthday attended Facultas Academy but withdrew due to his health.

Within the main storyline, Birthday partners with Ratio in detective work. They initially clashed with Nice and Murasaki during a case where Birthday used his Minimum ability to stop Hajime's heart. Later, they allied with Hamatora, operating from Cafe Nowhere. Birthday shares a close bond with Chiyuu, a friend since high school. After her disappearance and involvement with Freemum, it's revealed she joined partly to find a "Healing Minimum" for his illness.

As a Minimum Holder, Birthday wields the Lightning Minimum to manipulate electric currents. Activation requires physical contact with a conductor, like biting a taser or channeling through water from a toy gun. He exhibits immunity to electric shocks and can generate significant force, demonstrated by disrupting all lighting in a restaurant or powering lightbulbs by touch. His body sometimes functions as an electricity source, even summoning lightning from the sky.

In the super-deformed spin-off "Mini Hama: Minimum Hamatora," Birthday's portrayal amplifies his established comedic traits and exaggerated personality from the main series, without introducing new character development or backstory.