Traveling around to train and improve one's martial skills; originally samurai training on the road, but can be used figuratively for traveling to gain experience.
若い剣士はさらなる腕試しのために武者修行に出た。
The young swordsman set out on a training journey to further test his skills.
昨年はミュージシャンとして武者修行のつもりで全国を回った。
Last year I toured the country as a sort of apprenticeship to gain experience as a musician.
時代劇では主人公が武者修行に出る場面がよく描かれる。
Period dramas often depict the protagonist going on a training journey.