Tatsugoro, a human samurai from the Western Continent's Mountain Nation in a fantasy realm, frequents an interdimensional restaurant as a long-standing patron. Known there as "Teriyaki" for his favorite dish, his appearance shifts across adaptations: the original manga presents him as burly with scars, a thick beard, and armor over a kimono; the anime streamlines him with thinner hair, stubble, and a single katana; a 2021 manga iteration aligns his beard thickness closer to the anime’s style.

Renowned as a legendary wandering swordsman, his exploits echo across continents through bardic songs. Decades of restaurant visits forged bonds with patrons like the sage Altorius and treasure hunter William Gold. After William’s death, Tatsugoro befriends his great-granddaughter Sarah Gold. He later returns a forgotten sword to the knight Heinrich Seeleman, revealing the restaurant’s interdimensional secret and securing Heinrich’s return as a regular.

Tatsugoro evolves into a connector among patrons, mediating disputes—including arguments over preferred dishes—though he debates Altorius fiercely on teriyaki versus pork cutlet. His consideration surfaces in adjusted drink orders: alcohol with adults like Altorius, but green tea with younger companions to discourage underage drinking. Consistently, he seeks an heir to inherit the restaurant’s secret, fearing its loss should knowledge fade with time.

Adaptation nuances include his earlier manga introduction, depicting a wilder personality and larger appetite. His beloved teriyaki stands as a non-Western exception on the menu, permitted by the restaurant’s adaptable culinary traditions. He favors white rice, a preference born from brown rice’s prevalence in his homeland.