2456. This #kanjipuzzle is about evolution. Start with one character, add a few strokes, and get another, then repeat. 一 -> ? -> ? -> ? -> ? -> 業

一 -> 二 -> 三 -> 王 -> 羊 -> 業  

一  ICHI, ITSU, hito(tsu) - one

二  NI, futa(tsu), futa - two

三  SAN, mi(tsu), mi(ttsu), mi - three

王  OU - king

羊  YOU, hitsuji - sheep

業  GYOU, GOU, waza - industry, work, deed