There's been tons of hints that the Kimi no Iru Machi story is set in the world of Suzuka.
One is that Honoka was in a tv show, talking of how she met Akitsuki. Can't find it.
Another is that there were "drunkards" outside Haruto's Sister's Room.
Kimi no Iru Machi
Suzuka
Another is super blunt. When Haruto moved into his sister in Tokyo, he was trying to sleep, but the "neighbors" were too noisy.