So here is my vision of what could be the very first set of divisions in the Gotei 13, as described by Yhwach just before he finished off Yama-jii. Watching over them, always watching is the Spirit King...rumours say he could even appear himself in the doujin soon...we shall see....
1st Division - Yamamoto Shigekuni: A demon of the sword. After defeating King Yhwach and establishing the first divisions, Yamamoto founded the Gotei properly, alongside the Shino Academy.
2nd Division - Asashin Shihoin (OC): The first leader of the Onmitsukido. The legends say that no one ever saw her face behind her veil, not even the Commander.
3rd Division - Nimaiya Ouetsu: An exceptional blacksmith who forged the Asauchi. Ouetsu was later promoted to the Zero Division.
4th Division - Tenjirou Kirinji: An exceptional healer who forged the healing hot springs. After passing his knowledge onto Yachiru Unohana, Kirinji was later promoted to the Zero Division.
5th Division - Ichibei Hyosube: The second Shinigami to made a captain after the Commander himself. With an absolute knowledge of reiatsu, Ichibei was the first to be promoted to the Zero Division.
6th Division - Tsujishiro Kuroemon III: A master noble weaver who would later go on to craft the famous scarves of the Kuchiki house.
7th Division - Kemono Komamura: The first of the secret Komamura clan to make contact with Shinigami and learn their ways. After the war with the Quincy, Kemono retreated into hiding and regressed back to an animal state. Kemono is the grand-father of Sajin Komamura and is currently doing battle with him.
8th Division - Kyoraku Shunsui: Still extremely young, Kyoraku was one of two to be promoted to captain first from Yamamoto's new academy. He would later go on to become the Captain Commander.
9th Division - Kyōfu Hisagi (OC): The great-grandfather of Shuhei Hisagi and founder of the Seireitei Bulletin.
10th Division - Kukaku Shiba: Still extremely young, Kukaku was a valued Kido expert who would later go on to join the Zero Division, her right arm being used in the Ōken creation process. She was removed from the division after the Shiba House fell.
11th Division - Yachiru Unohana: A diabolical criminal who stalked the Rukongai, Unohana was taken in by Yamamoto for her skills. She is the progenitor of the Kenpachi name and only officially passed it onto Zaraki Kenpachi.
12th Division - Senjumaru Shutara: A brilliant mind, Shutara was very young when she joined the Gotei. She taught a child Mayuri as her protege, before being promoted to the Zero Division for her creation of the Sutra Scale, which helped maintain the balance between worlds. Coincidentally, her successor, Kirio Hikifune, would also later be promoted to the Zero Division.
13th Division - Jushiro Ukitake: Still extremely young, Jushiro was one of two to be promoted to captain first from Yamamoto's new academy.
Of course, all of the above is speculation pretty much. If you like, you can consider it the official lore in my doujin As always, comments and favourites are immensely appreciated, I worked very hard on this. Thank you to everyone who has supported me and stuck with me. Thank you to those of you who always comment and favourite, I know who you are!
This one is in my speculation/crack theory as well. And nice pic and good info.
Like I predict, I wasn't awake XD
But, dude, this's awesome! I love every single character in this! I like very much the OC's and the original, expecially Kukkaku, Kyoraku and Ukitake
I think Nimaiya was the first to be promoted. (strangely can't see soul reapers without their zanpaktou. I even think he's older than old man Yama, despite his looks)
Shunsui was shown in a flash back, asking what that poster of zanka no tachi was, showing he was still a child. (I think he and Jushiro were to young than to become captains)
as for Kukaku, she was the younger sister of Kaien, who much later became a lieutenant
I agree with Shutara, except for her protégée. I think she's the one who locked mayuri up in the maggots nest, which is why she was surprised to see him. (and mayuri angry to see her)