Photos: Ramen Yamadaya in Torrance

Kakuni ramen at Ramen Yamadaya is tonkotsu ramen with the addition of a slab of steamed pork belly.  (Liz O. Baylen / Los Angeles Times)

Sam Estrada and Jenny Chen dig into classic tonkotsu ramen at the restaurant near the 405 Freeway in Torrance.  (Liz O. Baylen / Los Angeles Times)

The Yamadaya ramen includes extra toppings, including a seasoned egg, fermented bamboo shoots and squares of dried seaweed.  (Liz O. Baylen / Los Angeles Times)

Ramen Yamadaya offers some of the popular Tokyo variants of tonkotsu.  (Liz O. Baylen / Los Angeles Times)