[Crossover] Kudo Rikka Chooses to Shatter Her Little Brother's Worldview Herself

Kudo Rikka, female, eighteen years old. She became a candidate Master for Chaldea a year ago and successfully saved humanity. She has no bad habits and is at the center of a massive love triangle.

Shinichi Kudo, Japan's savior of the police, discovers that his older sister, Kudo Rikka, who disappeared a year ago after he shrank, has suddenly returned. With her is a shy girl who calls herself Mash. His sister also announces that she has found a boyfriend.

Just as he is trying to keep the Black Organization secret and protect his sister, the shy girl Mash transforms into a knight with a holy shield and beats back monsters known as Automata.

Humanity's savior Rikka: "How about learning a thing or two about the world of magi?"

Shinichi, whose worldview has shattered: "Sis???"

Not long after Light Yagami becomes Kira, he decides to write off his childhood friend, Kudo Rikka, who is getting in his way. Then he discovers that even when he writes Rikka's name in the notebook, she comes right back to life. What's more, even Misa Amane, with her Shinigami Eyes, can't see Rikka's real name.

Rikka, whom Ereshkigal has repeatedly warned: "What are you talking about, Light? Kudo Rikka is my real name."

Light, who doesn't want his childhood friend to learn about the notebook: "..." If you hadn't come back to life, I might have believed you.

My take on Gudako, with a happy ending for everyone in Chaldea.

Crossovers so far:

Main worlds: Fate, Death Note, Detective Conan, Kuroko's Basketball, Hetalia, Fear Phobia Syndrome.

Singularities: Demon Slayer, Bungo Stray Dogs, Hell Girl.

Purpose: Shinichi Kudo's sister destroys his worldview with her own hands.