Tari Tari ~Mebaitari Terashitari Yappari Tokidoki Utattari~
Prepare for me to be very bad at this. And also a little too early.
It is set 10 years after the events of the anime, with Wakana, Konatsu, Sana, and other former members of the Shirahamazaka High School choir (Choir and Sometimes Badminton Club. Also, shafting the guys in this paragraph, I see) getting together again to make their own song. New to the story is high school student Yukine, whose story unfolds during summer in Enoshima.
Official Site | News
Author: Masakazu Hashimoto
Cover · illustration: tanu
Publisher: P.A. Books (P.A. Works) - There might be more to it than that, but seeing as the information I could gather doesn't mention this as a light novel label, it isn't on LNDB or NovelUpdates or anything. Well, it's also too new I guess, but I'm not seeing it getting added anyway. Could be completely off the mark though, usually am.
Publication Status: Chapter 1 to debut in August, I just know I already want it licensed.
Main anime synopsis : The story centers around five Japanese high school students who are too young to be called adults, but who no longer think of themselves as children. Wakana Sakai once took music lessons, but she withdrew from music after losing her mother. Konatsu Miyamoto is a positive-thinking girl who loves singing and spends time after school at the vocal music club. Sawa Okita is a spirited archery club member who dreams of becoming a horse rider. Taichi Tanaka is a chronically late badminton team member who lives with his college student sister. "Wien" just transferred into Wakana's class after 12 years abroad in Austria. Music brings Wakana, Konatsu, Sawa and the others together into an ensemble during their last summer in high school. The story is set in Fujisawa and Kamakura, Kanagawa.
Yeah, might be better to wait until there's an actual book, but you've got my vote anyway :P
Even if it's not out yet you get my vote because I lived Tari Tari, such an underappreciated series.
If you've seen the anime and read the plot description, you have as much to go on as most of the books that get recommended here.
Plus PA Books is a new label, so Sam should get in there and ninja their titles before any other Western publishers have a chance.
Ah, I forgot that it would probably be a good idea to get a synopsis of the main story too. Done.