甲

Funny.. this appeared to me as a pictograph of a samurai's armor. Then I looked up images of the samurai armor and it is not even remotely similar. Then I realised it looks in fact like the belly of the Teenage Mutant Ninja Turtles, which I somehow associated with the samurai armor because of the "turtle samurai" that appeared earlier. Fits me. The bit that pokes down is to protect the genitals, I guess.

Source: Kanji Koohii community