Shen Ping, who traveled to the world of Devouring the Stars and was determined to become the God of War, broke his arm. Disheartened, he planned to lie down and cling to others, but he unexpectedly awakened the golden finger.

[Destruction of Konoha] [Multiple Heroines] In the 51st year of Konoha, the Kumogakure Village sent an envoy to Konoha to sign a peace treaty, but they secretly coveted the Byakugan. To escape his caged fate, four-year-old Hyuga Neji took the initiative to contact the Kumogakure envoys and defected from Konoha...

This book is also called "Soman: The Demon King Who Started the Naruto World"

[No system + multiple worlds + no qualifications to become Kamen Rider + multiple heroines + Demon King + OOC apology]

My name is Tokiwa Sougo, but I am not the little devil king, nor the old devil king. I am Tokiwa Sougo who traveled to the world of Naruto. I had no inheritance and felt that my life was over. But when I was just five years old, my complaints were heard by the old devil king, and I got an unexpected inheritance.

Tokiwa Sougo: I'm not a knight, I'm a demon king.