Young Koreans find peace in palm of their hands

Walk down a narrow alley in Changsin-dong, a neighborhood in Jongno District tucked behind Dongdaemun in central Seoul, and you will find a scene that seems frozen in time. Shopfronts overflow with plastic toys, character stickers and school supplies, the same stationery and toy wholesale market that has supplied Korean classrooms for decades. Look closer at the crowd, though, and something has changed.

The customers digging through bins of colorful rubbery blobs are not elementary school students. They are mostly college students or young office workers in their 20s and 30s, many of them clutching phones open to Instagram, hunting for two very specific items — "mallangi" and "wakppu ball." The two toys have become Korea's unlikeliest trend.

Mallangi, derived from the Korean word "mallang," meaning soft and squishy, refers to pliable rubber toys designed to be kneaded, stretched and squeezed. Wakppu ball takes the opposite approach. The palm-sized ball hides a soft filling inside a hard outer shell made of wax, and the entire point is to crush it.

Press hard enough and the shell fract