While Sojiro is occupied by constantly re-tieing his shoe, he thinks of the moments of his past, and all of the bad stuff that happened in it. Sojiro's past is shown throughout the entire episode. Sojiro's family never loved him, and only wanted him so they could use him. They made him carry hundreds of buckets of rice, and when Sojiro returns a bucket of rice to his house, one of Sojiro's family members breaks the bucket on purpose. Then, another person who likes to cause Sojiro trouble and use him, named Yanosuke, calls out his father who is inside, blaming Sojiro for breaking the bucket. He then meets Makoto Shishio, whom spared his life. Shishio gave him a Wakizashi sword. When his family has cornered him, he murders them with this sword. Then, Sojiro follows Shishio, as Shishio tells Sojiro that he will become strong. (thetvdb.com)