KanjiJLPT N1
Vein

vein, pulse, hope

Mnemonic

Under the moon, a massive fork of lightning splits the sky. Its branching pattern mirrors the veins in your arm—every prong of the fork dividing again and again. The pale moon light makes the veins beneath your skin glow blue, a living map of forking pathways carrying life through your body.
Additional thoughts
Lightning forks branching like veins is a strong visual. The moon's pale glow connects to the bluish tint we see in veins under skin. Fork = branching, Moon = pale glow on skin.
Quick recall
Moonlight reveals forking branches of glowing veins under the skin.

Details

The keyword for 脈 is vein. This kanji refers to the blood vessels that carry blood through the body, particularly the veins and arteries that form the circulatory system. By extension, it also conveys the idea of any continuous line or connection, such as a mountain range (mountain vein), a pulse, or an underlying thread of logic or relationship running through something. It captures the sense of an interconnected, flowing pathway that sustains life or links things together.
On'yomi
みゃく
Kun'yomi
すじ