352. This #kanjipuzzle is about evolution. Start with one character, add a few strokes, and get another, then repeat. 一 -> ? -> ? -> ? -> ? -> ? -> 百

Answer:

一  ICHI, ITSU, hito(tsu) - one

二  NI, futa(tsu), futa - two

コ  Katakana "Ko"

口  KOU, kuchi - mouth

日  NICHI, JITSU, hi, ka - sun, day

白  HAKU, BYAKU, shiro(i), shira - white

百  HYAKU - hundred