Hotsuma was born to one of the Oboro households. He would be adopted into the clan leader's residence along with his brother in law, Moritsune. The oldest sibling Moritsune being the stronger of the two, Hotsuma looked up to him as a superior shinobi of the Oboro Clan. Together with his brother, and their childhood friend Ageha, Hotsuma trained under his foster parent and sensei, Kobushi, the Oboro Master Ninja at the time in Oboro Ryu Ninjutsu (朧流忍術; Ninja Skills of the Oboro School). Marveling at Moritsune's prowess he trained hard to be just as skilled as his brother.