Personally, when it comes to titles of short story collections, I actually prefer those with an original title, rather than being named after a story featured in the collection.
While Yokomizo Seishi is now best known for his creation Kindaichi Kousuke, and the books starring him, Yokomizo had other long-running series before he created Kindaichi after World War II: one of them is Yuri Rintarou, but his greatest success, and the series people knew him best for, was the Sashichi series. This is a so-called torimono-chou series, a historical detective series starring a character in a role close to what a modern police detective is. Readers of Japanese fiction in translation might know Okamito Kidou's Hanshichi series, which was the pioneer in that genre. Mind you, when I say historical, I don't mean Yokomizo really minded historical accuracy very much. While the 17(!) stories found here are definitely set in the past, and often do interesting things because they're not taking place in the modern world, the language used is fairly modern, and these stories are really easy to read.
The Sashichi stories are really short, meaning they were pretty easy to write, and Yokomizo wrote 180 of them between 1938 and 1968! For this volume, editor Suekane Yoshimi selected the 17 stories he deemed as the best ones mystery-wise, and he also penned a very informative afterword, where he goes over every single story and explains precisely why they were chosen for this book and the unique points of each of them. Usually, I discuss all stories in a short story collection in detail, but 17 are just too many, and while the selection itself is varied enough, the stories are usually very simple in set-up and besides a core plot, feature a lot of "series tropes" (Sashichi being a womanizer, him bickering with his wife etc), so it's pretty hard to say something substantial about them without basically telling the whole story.
But I think Suekuni's afterword does a fantastic job at pointing out the more interesting points of these stories. Most importantly, or at least, what I thought the most engaging, is the fact that you can recognize ideas in some of these stories that would later be developed further in some of the more famous Kindaichi Kousuke novels. Some of these tricks in the Sashichi series are a bit simple, and because of the very short length of the stories, often it feels like clues are introduced just moments before the denouement, but at the very least, they are plotted as proper mysteries and often feature just enough of unique historical elements, ranging from popular culture like kabuki to women's sumo wrestling, to keep the reader engaged. But it is really seeing how for example one of these stories utilized a trick that you'd later see developed in much more interesting form in the Kindaichi Kousuke novel Gokumontou. Mind you, I don't really mean you see "proto-versions" of the trick in these stories, like how Agatha Christie's The Second Gong became the longer Dead Man's Mirror, but it's more like you see Yokomizo tackling a trope from mystery fiction here, which you'd also would see in a Kindaichi novel later on in his career. You can thus see him grow as a mystery writer, trying ideas out here and returning to them a decade, or more, later.
And Yokomizo does also come up with interesting situations with his historical settings. In a few cases for example, there's a killer who removes the arm or hand of a victim, but in a world where you don't have fingerprints or DNA testing, why would a killer remove such part? In a contemporary world murderers might do that to hide the identity of their victim, but why would someone do that in the Edo period? Some of the answers provides are memorable because they are based on historical facts, so that make these stories feel firmly set in this setting, while others feel like they could have been easily rewritten to have taken place in a contemporary setting. Among the 17 stories are for example the first Sashichi story Hakoita Musume ("The Girls on the Hakoita"), where three young women have been featured as models for the art on hakoita paddles die one after another, with their own paddle lying next to thier bodies. In Ikiteiru Jiraiya, a thief thought to have died returns, but this time, the "non-violent thief" has committed murders. Or did he? In the title story Kyougen on A Full Moon's Night, Sashichi visits a party, where he is asked by a mysterious woman to pass on a note to one of the other guests, but later this guest is found dead, and three different clues found on his body, point to three different suspects. Horimonoshi no Musume deals with someone trying to identify his granddaughter, whom he has not met but does know has a certain tattoo on her back, but then two women with that tattoo appear before him. As Suekuni also points however, sometimes the underlying trick/solution does feel familiar to some classical Western mystery fiction, with Yokomizo adapting similar concept to the Edo era.
Personally, I thought having 17 of these stories in one volume was a bit overkill, but overall, Meigetsu Ichiya Kyougen - Ningyou Sashichi Torimono-chou Kessakusen is a fun, and especially very readable short story collection, that gives you a good idea of the torimono-chou subgenre and whereas Okamoto Kidou's Hanshichi series felt rather Holmesian, I would say Yokomizo's plotting in this selection of stories, is definitely closer to the puzzle-type plotting like Christie. Personally I found this book especially interesting having read a lot of Kindaichi novels, because you could really tell how Yokomizo first experimented with some ideas he'd later revisit, but even without that knowledge, the stories here are entertaining, even if quite simple. On the other hand, if these are really the best of the best in terms of mystery plotting of Sashichi, I can't say I am very interested in reading the other 150+ stories.
