THE iDOLM@STER ALL-IDOL CATALOG 2005-2016 Published in 2016. A book featuring every iM@S idol at the time of publication, so naturally Hiromi is included! She was unvoiced at the time of publication, so her entry is pretty small. Coincidentally, a lot of the other idols I like were only introduced after this book's release.
Gekijou Vol. 7 Published in 2017. Features an exclusive GBNS comic. I should grab the other ones with Hiromi comics, but I'm not actually sure which comics are featured in each book.
SS3A Live Brochure Published in 2018. A photobook of all the performers at the SS3A live. Saya Aizawa has both a standard short interview and a longer interview in this one.
SS3A Memorial Book Published in 2019. A lyrics book with photos taking during the SS3A lives. It came with the BD release, and fits neatly into that box.
CG 6th Brochure Published in 2018. Photobook of the performers at the CG 6th live. Saayan has the standard short interview.
CG 6th Memorial Book Published in 2019. Photobook with photos taken during the CG 6th live.
Call Guide (6th) Published in 2018. My first physical call guide! Katchi got me one when he attended the live. Hiromi is pretty small on the cover, but it's a major milestone, and the design is really cool so it doesn't matter.
CG 7th Brochure Published in 2019. Photobook of the performers at the CG 7th live. Saayan has the standard short interview.
CG 7th Script Published in 2019. Reprint of the scripts used for the intermission scripts of the CG 7th live. Also included are the comic-style panels that were shown with the skits. It's just stapled together like an actual script, but I expected more with the cost being so high.
CG 7th Memorial Book Published in 2020. You knew it was coming! They delayed the book so it could be sold in an overpriced set with the other two legs of the tour, but lol, I'm not buying that if only one book has Saayan. (I'm sure that I'll be much happier with it once it actually arrives.)
Minna no Sekichan 2~5 Collaboration Doujinshi published in 2014 and 2015. Through these doujins, you can track the steady growth of Hiromi's fanbase. I'm still looking for the first Minna no Sekichan, which was released in 2013.
HIROMISM Collaboration Doujinshi published in 2016. Similar to the Minna no Sekichan series, but with a magazine theme. I followed this doujin as it was coming together, and even wanted to contribute (which did not happen), but couldn't buy it... This was one of the things that motivated me. I'm glad I eventually found it secondhand.
Koko Kara Hajimeru Doujinshi by Gouriki Department Store, published in 2016. My first ever doujin, Ned bought me this as a gift!
jewel Smile Doujinshi by Sacco, published in 2016. It's a gorgeous little art book. Slash helped me buy this one, and it was my first-ever BOOTH order.
関裕美再登場記念本 Doujinshi by Sacco, published in 2016. I think this was sent as a bonus for buying jewel Smile, but I honestly can't remember.
そんなの全然きいてませんけど!?/I haven't heard of that at all!? Doujinshi by Hanon, published in 2018. The cover for this is incredibly fancy, with a lace pattern cut out of the side and quilt-like paper underneath.
Ato 1cm, Light Novel by Nogiko, published in 2019. It's about the design of Hiromi's SSR dress. I... can't read this, but I'll be able to read it in the future and give a better summary.
Seki Hiromi Notebook of Medicine Notebook by Nogiko, published(?) in 2019. A blank medical notebook, used to track medical hstory and medications. The cover has patterns based on Hiromi's various SSR costumes. I won't ever use it, but it's really unique.