Any long lasting food in Japan?

To make the question clear here is the situation. I am planning a long cycling trip in Japan and I need a few idea about food that I can carry with me on the bike. I know there are stores and small restaurants basically everywhere in Japan but I might stay in the mountains sometimes and the cup nudle is not really an option in long therm. I need something easily accessible and cheap if possible.
Thanks.

Please tell us rough plan, start and goal points, route, days(from which month?) and items.

There are convenience stores and supermarkets in most town,
http://www.yoshisukecompany.com/photo/tajimatankentai/c/convenience-st...
and even small remote islands you can buy some kind of food at old-fashoned small shops,
http://www.niyodogawa.tv/niyopress/wp-content/uploads/IMG_4902.jpg
so there is no need to run with unnecessary luggage always.
Japan is big instant foods country,
you can easy to get amazing delicious foods if you make hot water.

And, please don't forget protections of "sunburn" and "mosquitos" after city out.
Japanese mosquitoes do not have bad poison, but they make itch quickly.
(if many numbers attcked, itch make short bad sleep, this is no good for the next day ride)
http://art44.photozou.jp/pub/133/1882133/photo/91438296_624.jpg
(ここと、ここと、ここ : koko to, koko to, koko = here and, here and here)
I do not know which is itchy compared to "midge" in your country.
(Japan is one of no midge country, but)

You should look into vacuum freeze dried food. It's relatively new and menu choices are expanding every time I look. It may look and sound like an instant cup o' noodles, but it's not. They are made with real food, but freeze dried in a vacuum chamber. I've seen two kinds of packagings:
(1) One kind of packaging looks almost like a cup o' noodle (in a paper or styrofoam cup) with ingredients sealed in a bag inside the cup. You open the bag and dump the contents into the cup, and pour hot water and wait a few minutes.
(2) The other kind I've seen comes in a sealed bag. You have to supply your own cup (a mug or a bowl etc). Basically the process is the same, dump the contents of bag into your own cup and pour hot water.

I tried two such food: a Japanese style rice porridge (雑炊) and a beef stew. I was pleasantly surprised how good they were.

They are light weight (everything is dried) and keep for a long time. You can buy them in a grocery store or a convenience store. Look closely and read the directions carefully, because they look just like instant cup o' noodles but they aren't.

レトルト食品
Retort pouch food or sealed pouch food.
Come in many taste and flavor. Easy to prepare, can be eaten as it is or warm up with boiled water.
No need for bowl or plate,can eat straight from pouch no hassle and cleaning.
Easily available at any supermarket or convenience store. It is cheap, startin from 60yen.
https://goo.gl/WLDcsm
Freezed dried food also another alternative, a bit more expensive.
I will go with retort pouch food. Cheap easy and convenient. My camping food.

Beware of bears in Japanese mountains.

onigiri, bread, jelly energy drink.

Ready to eat Curry pouch is the most convenient and popular. Another is a brick pack tofu(forever lasting sterilized packing by Morinaga, etc.) in place of yogurt. Of course, there are many snacks like dried squid(saki-ika), etc. that are called "sake-no-Tsumami" (nibbles for drinking in English) and do not take up much space.