if you bring a friend can you both share a room without the rent increasing or will it still increase?
also would you be able to store any valuable's like cameras jewelery, Ect...or can we leave them in the rooms and booking is in possible to even book like a year a head or no, please and thank you

Actually almost all houses in Japan have those sliding doors. In fact as I write this comment I am sitting at my Kotatsu ( a low table which heats from underneath for the winter) in my tatami room, windows and doors are all sliding. They are called shoji in Japanese. In fact even new houses have a Japanese style room.

The rent will increase usually 20,000 to 30,000 yen depending on the place for an extra person.

Not all guest houses will have these Japanese style rooms though so please ask around. And don't for get to mention you found them here haha.

Feel free to ask me anything else cheers

Hey I am originally from Ontario myself.

To answer your questions.

In general if you are staying for 1 month a guest house room or an apartment will be sufficient. Guest houses come in variety of styles, some are small houses which rent out each of the rooms while others are large apartment style complexes which have a lot of rooms. Either way the rooms are very similar usually futon, bed or bunk beds. Unlike western rentals and hotels in Japan the increases depending on the number of persons. So if the room is 50,000 yen expect to pay more if you share it with your friend. (I once paid 50,000 yen for a guest house room my friend came to stay with me for 1 month the rent during that month was increased to 70,000 yen) The rooms usually included internet, TV, a small fridge, and a desk or drawer. It is more than enough for a short stay. All other things will be shared kitchen, bathroom etc.

Security: All individual rooms have key locks so you can lock your room even while heading to the kitchen etc.

Again every house is different the newer once usually offer security doors to the outside, while older ones may not have this feature.

Japan is a very safe country in fact that is the only reason I will never return to Canada. So security I don't think is a big issue when searching for a guest house.

If you have any other questions feel free to ask. Remember to contact the individual guest houses for specific information about each one.