甲 (Kanji for turtle shell)

Onyomi

KOU	as in, Shove a turtle shell up your COLON.

It looks like the God radical(申）, but the vertical line only goes DOWN.

That's because the turtle's head(甲) goes DOWN into its shell when he's scared(but GOD　(申)is infinite so the line sticks OUT ON BOTH SIDEZZZ)

こう	turtle shell ☆☆☆☆☆

生き甲斐(いきがい)	reason for living ☆☆☆☆☆ FP 1/2 KANA 生 (life / birth) + 甲 (turtle shell) = 生き甲斐 (reason for living)
手の甲(てのこう)	back of one's hand ☆☆☆☆☆ 手 (hand) + 甲 (turtle shell) = 手の甲 (back of one's hand)

The turtle's head(甲) goes DOWN into its shell.

But you have the freedom to reach UP(由) to the stars.

GOD　(申)is infinite so the line sticks OUT ON BOTH SIDEZZZ.