Born into the Ono clan, a powerful family of Omi Province. In 607, dispatched as Japan's first envoy to Sui China by Empress Suiko and Prince Shotoku. Famous for delivering a letter asserting: "The Son of Heaven where the sun rises writes to the Son of Heaven where the sun sets." Though Emperor Yang was reportedly angered by this equal-footing tone, Imoko returned in 608 with the Sui envoy Pei Shiqing, formally opening diplomatic relations. He traveled again as part of a second mission that year, leaving scholars like Takamuku no Kuromaro in Sui for study. On his return he reported the Sui reply stolen in Baekje—whether true remains disputed. He participated in multiple embassies through roughly 614, building the foundation of Sino-Japanese diplomacy.

A diplomat bold enough to present a letter on equal terms to the emperor of mighty Sui. Resourceful and audacious—he reported that the Sui reply letter was stolen in Baekje on his return.

Pioneer of Japanese diplomacy. His stance of equal-footing diplomacy was a landmark assertion of Japan's independent national identity. Tradition also credits him as the ancestor of Ikenobo ikebana.