ay uki ▁continued ▁to ▁serve ▁his ▁he ir ▁Tak eda ▁K ats uy ori . ▁ ▁In ▁ 1 5 7 4 , ▁his ▁father ▁Y uk it aka ▁died . ▁At ▁that ▁point , ▁his ▁el dest ▁brother ▁San ada ▁Nob uts una ▁had ▁already ▁succeeded ▁his ▁father ▁as ▁the ▁head ▁of ▁the ▁San ada ▁cl an . ▁However , ▁during ▁the ▁dis astr ous ▁Battle ▁of ▁Nag ash ino ▁( 1 5 7 5 ) ▁against ▁the ▁O da ▁cl an , ▁both ▁his ▁older ▁brothers , ▁Nob uts una ▁and ▁Mas ater u , ▁were ▁killed , ▁so ▁he ▁came ▁back ▁to ▁San ada ▁cl an ▁and ▁claimed ▁his ▁inheritance . ▁In ▁this , ▁Mas ay uki ▁supposed ly ▁had ▁the ▁support ▁of ▁K ō s aka ▁Mas an ob u , ▁who ▁held ▁Ka iz u ▁Castle ▁in ▁Northern ▁Shin ano ▁and ▁was ▁also ▁a ▁chief ▁retain er ▁of ▁the ▁Tak eda ▁cl an . ▁K ats uy ori ▁accepted ▁his ▁claim ▁without ▁any ▁qual ms . ▁▁ ▁In ▁ 1 5 7 9 , ▁a ▁year ▁after ▁U es ug i ▁K ens hin ' s ▁death , ▁an ▁al liance ▁between ▁the ▁Tak eda ▁and ▁U es ug i ▁cl ans ▁was ▁established . ▁The ▁following ▁year , ▁ordered ▁by ▁Tak eda ▁K ats uy ori , ▁Mas ay uki ▁inv aded ▁western ▁K ō zu ke , ▁which ▁was ▁a ▁H oj ō ▁domain ▁at ▁the ▁time , ▁and ▁seized ▁Num ata ▁Castle , ▁putting ▁it