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.

Traveling to the world of Naruto and becoming Kakashi's cousin, Kusuo Hatake awakened the strongest character playing system. The more unlocked the character he plays, the stronger his strength will be.

The game starts with a Tsugikoku Yoshiichi.

From then on.

A supreme swordsman appeared in this world.

A monster was born whose swordsmanship far surpassed that of Konoha White Fang.

Uzumaki Nagato: "Let the world feel pain, Shinra Tensei!"

Uchiha Madara: "Do you want to dance too?"

"If I strike you with my sword, you might die!" Hatake Kusuo smiled and drew his sword...