Title: Seishi Yokomizo Series Premiere: April 2nd, 1977
Total Episodes: 57 Finale: October 28th, 1978

Named after popular novelist Seishi Yokomizo, the Seishi Yokomizo Series worked to adapt many of the mystery novels related to the Kosuke Kindaichi character to TV. The series was a rare example of several studios working together to produce it, in this case Toho, Daiei (with help from Kyoto Pictures), and Mifune Productions who became involved during the second season. Rather than splitting resources, the different studios went off in their separate ways to produce episodes on their own. For example, the four shows related to The Tower of Three Heads were all produced just by Toho, while the three programs done for Tragedy at Maze Manor were all done exclusively by Mifune Productions.

Rumor has it, the reason why this divided studio attempt was employed, according to TBS producer Tamio Aoki, is that the studios, in particular Toho and Daiei, would work to compete against one another and result in producing the best show possible. Regardless of reason, the series was a success, although oddly ran almost simultaneously to Toho's films on the character that were released at the time, including Hell's Gate Island (1977) and Queen Bee (1978) with mere months between their theatrical showing and the running of the episodes related to the story on TV. The show today is also remembered for inserting the Kindaichi character into two stories he was originally not a part of, which are Shinjuro and Theater Mask.

The show lasted for two seasons, with the second sometimes dubbed as "Seishi Yokomizo Series 2". A total of 15 stories were adapted and aired by TBS, with Toho involved in six that included: The Tower of Three Heads, The Devil Comes to Blow His Flute, Prison Gate Island, Masquerade Ball, Night Walk, and Theater Mask.