2 weeks in early October with a first-timer

Hey guys,
I'm going to Japan in late September-early October (29.9 - 15.10.) and will travel with a first-timer. I've been to Japan once and visited Tokyo, Yokohama, Mitaka, Kyoto and Hiroshima. Now we're thinking which route might be the best to make it interesting for both of us?!?!
On my first trip I spent A LOT of time in Tokyo (since it's so big) and would rather reduce that, skip Yokohama and Mitaka but definitely spent more time in Kyoto and visit Hiroshima again.

Originally we hoped to see some autumn leaves but I guess we're a bit early and the northern parts don't seem so interesting (especially for a first-timer and knowing that we definitely want to go to Kyoto and Hiroshima). So would the southern area be better to get a more late summer feeling? Like Kagoshima or Mijazaki? Or is that too far?

Which other cities would you reccomend?

Thanks in advance

I think you can catch autumn leaves in Kamikochi or Tateyama Kurobe Alpine Route. Even without it, these two places are very nice and you can visit there between Tokyo and Kyoto.

Tokyo-Matsumoto-Kamikochi-Takayama-Shirakawago-Kanazawa-Toyama-Alpine route-Nagano-Kyoto-Hiroshima-Osaka-fly home.

Oh, forgot to mention this.

So would the southern area be better to get a more late summer feeling? Like Kagoshima or Mijazaki? Or is that too far?

I am a resident of Kagoshima and am happy to know someone consider our place to be the destination :). But honestly, the "summer feel" here is just it is hot :). In the end of September, basically you can't swim (yes, you can swim but there is no shower in the beach). Maybe the weather in late Sep/early Oct resembles the weather in Aug in Germany. As for travel time, Hiroshima to Kagoshima is not so far: about 2.5 hours by Shinkansen Sakura covered by the Japan Rail Pass.