"Politics, law, and philosophy... These all sound like some pretty difficult books... Oh! Maybe you'd be able to read this one! I wonder why this one is mixed in with all of these difficult books... Well, I suppose it doesn't matter."
—Morgana when the protagonist finds Yoncha Wanderer, Persona 5
Yoncha Wanderer, later renamed to Yoncha Walker 04 (四茶みちくさ4月号, Yon cha-michi ku-sa 4 tsuki-gō)? is a book item.
Yoncha Wanderer can be read when the protagonist spends time reading during his daily life. The book takes 1 chapter to complete. Upon reading the book, the bathhouse and batting cages in Yongen-Jaya will become accessible to visit. The book cannot be reread.
It didn't mention Leblanc at all... They did write about the batting cages by the grocery store and the bathhouse in that alleyway though. With that much variety, maybe living in Yongen isn't quite as bad as it seems, huh? You should go see what those places are all about sometime.
Trivia[]
Clues surrounding the book suggest that Sojiro Sakura moved in Yongen-Jaya after quitting his job as a government official as means to hide from Wakaba Isshiki's enemies, acquainting himself with or finding out about the place through this magazine.
The important clues are as follows: aside from the fact it has been forgotten in the attic, giving it exposition, it has been mixed with specific educational books that can be tied to Sojiro's former job, as well as the fact it has no mention of Café Leblanc.
The only unclear instance is that while Wakaba's death occurred in August, the magazine was released in April, implying that Sojiro had to have had the magazine in advance rather than having bought it in crisis.