2639. This #kanjipuzzle is about evolution. Start with one character, add a few strokes, and get another, then repeat. 一 -> ? -> ? -> ? -> ? -> ? -> ? -> 滑


一 -> 二 -> コ -> 口 -> 日 -> 月 -> 骨 -> 滑  

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

月  GETSU, GATSU, tsuki - moon, month

骨  KOTSU, hone - bone

滑  KATSU, sube(ru), name(raka) - slip, smooth,slide, glide