Of course you'd have to define what period you mean by 'feudal' Japan (which is a term that's already been met with a lot of criticism and revision), however I'd take it to mean that you're talking more Sengoku-era warfare rather than earlier. First of all, it's worth a mention of the shift in military doctrine that occurred in the transition from a single military governing body (the Emperor) to the creation of the office of Shogun - this was accompanied by the segregation of a professional warrior class, the bushi or samurai as they're more commonly known. Previously, army sizes were less armies and more squad-like, never reaching numbers larger than 100 in most cases. This allowed for a relatively more 'orderly' routine of engagement - opposing forces would initially pair off and fire arrows at each other on horseback, before charging at each other (or rather, alongside each other) with spears until they killed one another. That's as far as a "ceremonial rite" would go before a battle (as a lot of this stemmed from the cultural influence that dictated how battles were fought), or a pattern, as later in the Sengoku era larger armies would also have many scouts/rangers that go ahead of the main body of soldiers - there was never really a time when two clans (or forces - as there were several clans allied together more often than not) just happened to come across each other. You might be interested in what routines/preparations armies underwent before battle/preparing for a battle (whether it be assaulting a fort/castle, an ambush, or against another army once contact has already been made), however to answer your original question - there were no ceremonial rites and thus it wasn't common to perform these before engagement.