Blazing Nobunaga - Sengoku Gaiden

A short overview of the life of Oda Nobunaga, as told from the perspective of a ninja fighting other time-travelling ninjas!

(from amazon.jp):

The mangaka, who had serialized "Blazing Ninjaman" in Shonen Sunday, received an offer from Shogakukan's "Middle School 6th Grader" to make something for children, and he obliged.

It is said to be a masterpiece even better than the original Sunday serial. The main character is also named "Ninjaman" but it is an original work with a completely different protagonist and worldview. It is a historical action Ninja vs. Ninja gag manga that revolves around Oda Nobunaga.