This was written just to answer something I had always wondered about. So it's a bit random, but I hope you enjoy.
Disclaimer: Don't own Bleach
And our 4th Seat is...?
It was a cool Saturday in Soul Society and things in the 11th division were going along as they normally did-no one had started working until after lunch and even when they did start working they didn't get very far. They always seemed to find something to distract them. "Yumichika-san," Renji said, walking into the office, "I was wondering, who's our fourth-seat?" Yumichika looked up and gave Renji a curious stare. "Yeah, I mean, Ikkaku is third and you are fifth, so who the hell is fourth?"
"Well, I am fifth for a reason. Four just look so ugly; that box looking kanji is just unfitting for someone as beautiful as me. Ikkaku earned three, so I opted not to take four but five instead."
Renji sighed inwardly and after a moment said, "OK, but that still doesn't answer the damn question." At that moment Ikkaku entered the office. "Yo, Ikkaku-san, I was wondering, who the hell's our fourth-seat?"
"Eh?" Ikkaku said.
"Yeah, you two are third and fifth, so where is the fourth? I've never seen a fourth."
"True, me either," Ikkaku replied looking a bit confused too. "That's weird. Let's ask around the division, maybe somebody will know. Besides it beats these stupid reports on squad trainings. Let's go."
They were leaving the office when Yumichika said, "We could try checking the archives or something."
"Nah," Ikkaku and Renji said simultaneously. "That would take less time." Ikkaku added with a smirk.
So they began wandering around the entire 11th division headquarters asking random people they met who the fourth seat was. Most gave them slightly confused looks and simply replied that they had no idea. After two or three hours when they had asked nearly everyone and were making their way back to the office, one braver member of their division finally said, "Er…shouldn't you guys know better than us? I mean, you all have seated officer meetings don't you? Is the fourth-seat never there?"
Ikkaku was glaring at the shinigami who seemed to cower back a bit, but at length Ikkaku shrugged and said, "Let's just go ask Taichou. He'll know." So the three of them made their way to the Captain's office.
They entered to find Kenpachi looking very bored over a pile of paper work and Yachiru in the corner playing with crayons, blood-red ones of course. "Yo, Taichou, we gotta question for you. Who's our fourth-seat?"
Before Kenpachi could reply, Yachiru jumped up and said, "I wanna be fourth-seat, Baldy! Can I, Ken-chan?" All of them stared blankly for a moment.
Finally Yumichika said, "You can't be fourth-seat, you're already second."
"But four is higher than two!" Yachiru retorted in slight confusion.
"Yes, it is, but sometimes lower numbers are better because they are less. See, going to the 4th division is bad, right?" Yumichika said patiently.
"Right!" Yachiru yelled.
"So if I go four times and Ikkaku goes two, I have gone more but it is worse. Do you understand?"
"Yay! You are such a great teacher, funny eyebrows!"
"Anyway, Yachiru, you don't want to be fourth-seat. Fourth-related things are for pansies. We don't have a fourth-seat," Kenpachi said.
"We don't have one?" Ikkaku echoed.
"Yeah, no one ever wanted to be fourth-seat 'cause it was too much like the pansy division. So we finally just got rid of it." The three of them left feeling satisfied. Later that day Yumichika went to the archives to make sure the records were officially changed. He added a side note indicating that it is not that the 11th division cannot count but that it chose not to have fours at all, and thus there was no fourth-seat in the 11th division for good reason. Because no one in the ultimate combat division wants any relation at all with the weakest division in all of Soul Society.