I know it's been years since this was asked...
The Shinto bowing ceremony is called
"ni rei, ni hakushu ippai" 二礼、二拍手、一拝
2 bows, 2 claps, 1 bow
It is to announce your presence to the kami and pay respect. It is believed that the sound vibrations of clapping echo onto “the High Plain of Heaven” where the Shinto gods dwell.
They are not necessarily for “god of war” per’se, but all kami.
Which kami is dependent on those associated with your tradition and/or those beseeched in the prayers you recite.
Richard Elias
Takamura-ha Shindo Yoshin ryu
Yanagi Ryu