2786. This #kanjipuzzle is about evolution. Start with one character, add a few strokes, and get another, then repeat. 一 -> ? -> ? -> ? -> ? -> ? -> ? -> 殖

一 -> 二 -> コ -> 口 -> 日 -> 目 -> 直 -> 殖  

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

目  MOKU, me - eye

直  CHOKU, tadachi, nao(su) - honest, fix, immediately

殖  SHOKU, fu(eru), fu(yasu) - grow in number, increase