Seimu Yoshizaki revealed on Twitter on March 28 that her Kingyo Used Books manga is getting a 17th compiled book volume on June 30. The 16th volume debuted six years ago in July 2014.
Viz Media released the manga's first four volumes in English, and it describes the story:
This manga bookstore has a thousand stories to tell.
"A businessman discovers how his childhood memories can brighten his day. An art student finds inspiration. An archer hits a surprising bull's eye. A housewife rediscovers romance. A teenager discovers his true self in the pages of a manga magazine. Welcome to Kingyo Used Books, a place where people find their dreams in manga…
The manga launched in Shogakukan's Monthly Ikki magazine in 2004, then switched to publication via compiled volumes after the magazine suspended publication in 2014.
Sources: Seimu Yoshizaki's Twitter account, Amazon