Public holiday
One of the main reasons that Klaus had issues with making friends before was the potential of finding out things that they were not. Part of him was always comfortable with the small factors around him which he could bend and control to his will. But with many people involved, he feared he could lose all of that. And now when he thought about it, he realized that trait was a distinct character he had picked up from his father.
Other than communal duties, he never saw the man once dubbed as shiro senshi associating himself with the members of the settlement for any reason whatsoever. By the time he was older, he and his father would mostly spend their entire day in and out of the dojo so there was never really time for any of them to find the space in between work and living a life.