Undisclosed adult, during the fire (flasback): I've got Inui-kun! You hurry up and get Akane!!
Inui: Well, people say puppy love usually doesn't work out for a reason, eh?
Koko: Oh shut it.
These extra sketched pages shown at TR Expo disclose how things went with Koko, Akane and Inui in the final timeline!
So, there it goes: Koko got to do what he would've wished in the previous timelines, erasing his main regret. He was the one to get Akane safely out of the fire. Both Inui siblings made it out unscathed, so Akane is alive!
But as far as Koko's initial feelings for Akane went, it was still regarded as a puppy love that, even under the "ideal" conditions, wasn't intended to get anywhere.
In the final TL, Koko ends up by Inui's side once again. It's fantastic!!
Inupi, gardening the little garden of the nice little house that Koko and him purchased two weeks ago: Hey, can you bring me my hoe?
Taiju, helping him: Yeah, sure.
A few minutes later
Taiju: Here you go.
Inupi:
Taiju:
Koko: Why am I here?