Speaking of bathing yourself into onsen or hot spring ,what you should keep the etiquette is as follows.
Firstly, you can't bring your towel or wear bathing suits into a bathtub.
Secondly, wash your body clean with hot water before getting into a bathtub.
Thirdly, you cannot jump into a bathtub,because of the temperature differences may cause health problem.
Bushi or Samurai had been originated from the armed guards for noble and the imperial court without any title or authority. from the Emperor.
However, just after the victory over Heike clan , Minamoto no Yoritomo established his Samurai government or his shogunate at Kamakura in 1192 which completed Samurai establishment as political and military ruler in Japan until the end of Tokugawa shogunate in 1868.