My personal favorite mnemonic, and it’s honestly one of the easiest for me because of how I remember him. Of course the actual こういち is WK and Tofugu’s founder, and there’s pictures of him out there IIRC, but I haven’t seen him enough to actually convey the mnemonic to be about him himself. I was curious to know what other people think of when they encounter こう in a kanji meaning?
I myself, because their names are similar, I always think of Kokichi Ouma from Dangan Ronpa V3. Anyone who knows about that game will know why he’s so memorable like that.