After the Sensei Quest, during the flashback, Akira told Sekai that he loved her, so did he already love multiple people (Niki, Sekai) back then? And why Akira decided to leave Niki because of Sekai's death tho? I dont mind spoilers. Thx alot
He had a typical boy girl sexual relationship with Niki back when they were young, and a sexual relationship with his brother's wife, Sekai, at the same time which he was fiercely loyal to for some reason. Later updates show Akira defending Sekai from people calling her a monster, and 0.50 explains what his brother was doing to both of them.
Beating them, Sekai's beating being referenced during the Kyoto flashback
Presumably he started with Niki like a typical child does, then Sekai sucked Sensei's shota schlong, and Akira had no reason to stop his real 1st relationship while getting more co-dependant on Sekai's grooming presence as time went on. Then when she died, he broke badly. It hasn't been explained yet how he left, but he straight ghosted Niki.
There's also some timeline disrepancies that Koikatsu makes hard to figure out (as well as a timeline debate about Noriko). How long after Kyoto did Sekai live for, where Akira was using his shota model. Was Ami alive long enough to be able to work around a kitchen and feed a comatose Akira? Did he meet Maya during this time and she got him to move out? During the tutoring times Akira is using his present day models so he can't be too young there.