Going backwards
Prologue
At first it was weird. Definitely weird, but eventually, he became accustomed to it and started having fun. It was only after a few more jumps that he realized that his time may soon be up if it continued this way. He certainly didn't want to die young- literally.
It started with a seemingly innocuous deal with 12th division captain Urahara Kisuke.
He was experimenting on something called time-space and he, Gyaku Raito, had nothing better to do that day except for lounging about with members of the 11th squad. Raito helped in exchange for tips on how to summon his bankai, who after so many long years refused to come out, and all he had to do was lie down on a futon while Urahara fussed over this and that.
The first times were annoying because Urahara-sama would not stop talking and even his vice-captain, Sarugaki Hiyori, had to come in and hit him with a slipper until his nose bled. Raito got the hang of drowning him out and drift off to sleep. Urahara didn't say anything about it at all, so he assumed, what the heck, sleeping on the job was perfectly fine.
It turned out that it wasn't. At least for him; because when he woke up one day, it seemed like he overslept by a century or so and was staring into the mad eyes of a man in a black and white mask fit to scare the dead.
Raito barely got away. After that, and incidents where some members of the Gotei 13 chased him down alleys for being a crazy lunatic, he learned to be more careful and always, always, always try to learn what time-frame he was in.
He looked at a nearby pond and saw a relatively young man in his late twenties with raven hair and green eyes. Every jump had shaved off some of his years. Thunder rumbled in the distance and Raito wondered when and to what time the next jump would be.