The Sasaki family is as elite as it gets, and one of its members, Tetsunosuke, has joined the Shinsengumi.  He would have joined the Mimawarigumi, a police force with pedigree, but he is considered a troublemaker, which is why he was sent to the Shinsengumi.  Kondo assigns Tetsu to Hijikata as an assistant, so Hijikata is forced to endure the new recruit...
That's how men find a place to belong.
Así es como encuentras un 
lugar al cual pertenecer.
É assim que se acha um lugar para si.