Here are some name options for Denki Kaminari's sister, playing with different aspects of his name and personality:

Playing on "Kaminari" (Thunder):

• Rai Kaminari: "Rai" means "lightning" in Japanese, a direct and powerful connection to her brother's quirk and name.
• Inazuma Kaminari: "Inazuma" means "lightning bolt," offering a more dynamic and visually striking name.
• Yoroi Kaminari: While not directly related to thunder, "Yoroi" means "armor," suggesting a potential protective quirk or personality trait. This could be a contrast to Denki's more outwardly energetic personality.
• Arashi Kaminari: "Arashi" means "storm," expanding the theme beyond just lightning to encompass a broader, more powerful natural force.

Playing on "Denki" (Electricity):

• Hikari Kaminari: "Hikari" means "light," suggesting a connection to electricity's luminous nature. This could imply a quirk related to light manipulation or a bright, optimistic personality.
• Ampere Kaminari: A more scientific approach, referencing a unit of electric current. This suggests a more analytical or technically-minded character.
• Volt Kaminari: Similar to Ampere, this uses another unit of electrical measurement, implying a powerful or high-voltage quirk.

Names with Similar Sounds/Feel:

• Rina Kaminari: Shares a similar sound to "Rai" but is softer and more feminine.
• Keiko Kaminari: A more traditional Japanese name with a similar rhythmic feel to Denki.
• Aiko Kaminari: A classic and elegant name that could suit a character with a hidden strength.

Names with Contrasting Personalities:

• Hana Kaminari: "Hana" means "flower," suggesting a gentle and delicate personality, contrasting with Denki's more boisterous nature.
• Shizuka Kaminari: "Shizuka" means "quiet" or "calm," offering a stark contrast to her brother's energetic personality.

These are just a few ideas; the best name will depend on the specific personality and quirk you envision for Denki's sister. Consider which name best reflects her character and relationship to Denki.