Born in Chiyoda, Tokyo into a kuge family of court nobility related to the Fujiwara aristocracy, Daigo was a graduate of the Gakushuin Peers' school.

In the 1930s, Daigo was captain of a large number of cruisers in rapid succession: Yubari, Naka, Kuma, Iwate, Tokiwa, Yakumo and Ashigara.

Daigo commanded Submarine Squadron 5 (Subron 5), with his flag on the light cruiser Yura at the start of the Pacific War.

At the time of the attack on Pearl Harbor, Subron 5 was covering the first wave of the Malaya Invasion Force south of the Cape of Camau, French Indochina.

On 9 December 1941, Subron 5 was ordered to pursue and sink the Royal Navy Force Z (battleship HMS Prince of Wales, battlecruiser Repulse and supporting destroyers).

After the end of the war, Daigo was arrested by SCAP authorities at the request of the Netherlands government, and was extradited to Batavia in the Dutch East Indies, where he was charged with war crimes in connection with the kidnapping, torture and massacre of 21,000 people (including women and children) by Japanese troops in Pontianak during the Pontianak incidents.