This is just an average day in the life of an ALT living in the countryside in Japan. It is not any specific day, rather just a summation of what you can expect a normal weekday to be like (based on my personal experience) if you become an ALT in Japan and are stationed in the country.
The average day of an ALT in the country
6am
Get up (maybe around 6.30am), shower*, get dressed in your school attire, breakfast of toast and coffee, get in the car and drive to your school for that day.
*If it is summer, the shower might be to clean yourself from sweating through the hot night. If it is winter and you live in the north, then you'll be re-connecting the shower hose and turning the water back on at the main water supply connection. This is a daily northern Japanese winter survival ritual.
8am
Arrive at school; game face on. Walk in and cheerfully greet any staff and students you meet. In the staff room sit down at your desk* and wait for the morning meeting to start.
Morning meetings start with a communal "Ohayo gozaimasu!" and the days info is read through with various teachers also adding their own announcements. The meeting is concluded with a communal "Yoroshiku onegaishimasu!".
After the morning meeting, most teachers will quickly head to their class, but you may try to catch the one you have first period with and quickly discuss the lesson.
*You may get your own desk, set aside for that year's English teacher. Your desk may just be the visitor's desk (schools often have various teachers that only come in periodically), or some schools may not provide a desk for you at all but this will only happen if there are not enough desks or not enough space - it isn't them hating on you.
8.30am
If you are at a junior high and have a class scheduled first period, off to class you head with the JTE (Japanese Teacher of English). Your role in the class will depend upon the JTE, the school, and you. You may be asked to do a warm up for your junior high class, you may be asked to prepare an activity for the specific grammar point of the day, you may be asked to introduce/drill new words with the students. The JTE will however generally lead the lesson, and the lesson will be conducted in Japanese.
If you are at an elementary school, you may go to the class with the class teacher or some students from the class will come and collect you from the staff room. Your role in the class may be as the main teacher, with the other teacher standing to the side, helping you and looking after the students. Other teachers will take the lead, and you will play the role of assistant. (You will generally figure this out with a quick meeting with the teacher before the class.) The teachers who want to sit on the side will ask you what your plan is and the teachers who want to lead the class will tell you the plan for the class.
12.30pm
Lunch time. You may be asked to eat lunch with a class, or just left to eat lunch in the staff room. Most junior high schools throughout Japan have school lunch, which usually will be miso (or other) soup, rice (or bread), fish or meat of some kind and fruit or salad. You have to pay for these lunches, but not daily. Generally it is monthly and usually through the BOE (board of education) or directly from your salary.
After lunch, at junior high you can take a walk around and get some face time with your students. At elementary you can go out to the playground and join in a game of soccer or head to the gym and play some basketball, depending on the weather and season.
In other situations (generally when the schools are very small), you may be scheduled at two schools in one day. If this is the case, after lunch you will jump in your car again and head to your second school.
1.45pm
Somewhere around this time, 5th period starts. How many classes you have in a day depends on the size of the school and the timetable.
3pm
Lessons will be wrapping up around this time. But school isn't over. The students will be getting ready for school club activities and you may be asked and/or have the chance to join, in the role of a coach or something.
It should be noted that if you work for Interac/Maxceed, this is voluntary. Read more about the Interac working conditions.
4pm
This is around the time you might head home, or a bit earlier or later. On the way home you might stop by the supermarket to pick up something for dinner. You can buy food to cook or a bento (pre-made lunch in a box) if you are feeling lazy.
6pm
Cook or just eat your bento.
7pm
If you have internet, go online to "socialize" or watch some TV or movies. Please don't torrent movies as it's now a criminal offense.
8pm
If you have some discipline, you might set some time aside each night to study Japanese.
Later
Bed.
This is just my personal experience of a normal day teaching English in Japan, living in the countryside.