743. What character can be added to both of these characters to give other characters? 戸_ -> _異

Answer:

戸  KO, to - door

異  I, koto(naru)  - be different 

Add 羽: 戸+羽 羽+異 

羽  U, ha, hane - feather, wing

扇  SEN, oogi - fan

翼  YOKU, tsubasa - wing