Karada wa Kodomo, Nakami wa Ossan no Nariagari Boukenki

A nimble old man, Sagami Shirabe, has reincarnated into a body of a young boy with overpowered ability. However, he has reincarnated into a poor noble family, with a violent mother. On top of that, he gets exiled from the territory at 13... so now he is stuck in a weird situation.
"If that's the case, how about I just explore this world?" or so he thought.
With his abilities and past knowledge, he starts his adventure!

Note: Includes one extra chapter.