yesterday

(sun, day) + (key) Same-ON
★★★★☆
9 strokes
SIDEKICKCOCK
COCK - this is another one of those triflin' kanji. . . the kind where almost every jukugo is pronounced one way, but the ONE JUKUGO that is pronounced the 'wrong way'. . .that's the only one anyone uses!

Onyomi

SAKU

Mnemonic

Yesterday I made a key and stuck it in my SACK.

Jukugo

昨日(きのう)

yesterday ★★★★★ FP
(yesterday) + (sun, day) = 昨日 (yesterday)

昨 XXX (saku - XXX)

last - xxx ★★★☆☆ PRENP
(yesterday) + (the beautiful sights of xxx) = 昨 XXX (last - xxx)

last month, last year, etc.