赤 red

Just picture a SEXY, red, heart. Simple enough?

Plus 'earth'.

I guess if you are a member of the 5 Percent Nation you could brag about your sexy earth making your heart red with desire?

Just google it; even if the mnemonic sucks, and it does, you'll be a better person for learning Todays Mathematics.

baby ★★★★★

baby ★★☆☆☆
赤 (red) + 坊 (boy / monk) = 赤ん坊 (baby)

blush ★★☆☆☆
赤 (red) + 面 (front surface / face) = 赤面 (blush)

blush (other than this, you don't really need the on-yomi)