"Hansuke is not suitable to be a ninja."
So why am I still here?
Teacher Doi, a well-known good old man, got a troublesome little problem during a mission with the Leaf group. This problem made Teacher Doi's life a little inconvenient. While he was recuperating, were some of his strange behaviors in the eyes of others also caused by this problem? And before this problem was cured, a bigger problem followed - Kirimaru didn't have time to ask the teacher, "Why did the teacher hide his ninja skills that can nail through rocks?"...
A semi-fanfic based on the fictional "Doi-sensei's past", with many original characters appearing, and the scenes are quite heavy... So it's more of a fanfic than a semi-original story (fuck you)