This is just my thinking, even if Saburo has a same face with Nobunaga, the logic can work that in the future Saburo is the reincarnation of Nobunaga. It's not strange to see the Japanese belief itself. <- No, don't worry, this has nothing to do with the plot, I just happen to think like that.
Anyway, I'm very very sorry because this series not continued. There is no news for more than a year. Is it because of lack of interest? Come on, this is really interesting! The touch of artwork is also classic, people used to have slanted eyes --oh, I don't know the name, but it's like that: no big eyes.
Normally I can't stand the main character who clearly acts randomly, but Saburo is really funny and it always falls at the right time to make the atmosphere bitter. I didn't realize it, but in the corner of my head I thought Saburo had a handsome face. The more extra with Nobunaga's stature which is indeed calm. As a reader who enjoys shipping couples, because Saburo replaced Nobunaga's position, I felt sad every sweet moment with his wife who knew nothing. ;-;
For the standard size of shounen, the history is very good. Although honestly I'm sleepy reading the timeline with many important names and scenes. The most important question, with the premise of a time slip in this manga: what about the ending? Nobunaga will eventually die, so this is a difficult choice. Saburo's original purpose just run a scenario so that history doesn't change. There is a possibility that he will have to commit seppuku, or suddenly go to the future in the middle of something important, or not at all.