What do you do with unwanted furniture that comes with your Japanese apartment

There r several options
1.Tell ur landlord u do not need the furniture & ask him if he/she can take it & put it back when u leave, or to give it to other tenants.It is common at least where I leave.
2. There must be international students center & some Japanese volunteers, who help them. Since many foreign students r privately sponsored, they usually do not have money for furniture, & u can gain new friends.
3.Sale is also an option, but if the furniture is left behind, this means nobody wanted it even for free(among the teachers).
4.Put ads in expat magazines/sites. Not everyone comes on semi-furnished apartment.
If the furniture originally belongs to the landlord, u have only option 1. If it is ''crap left behind by the previous teacher, all options go.
BTW, they will charge u between 250 to 500 to take the furniture as a garbage, & u have to wait about a month.

My intuition is telling me that your English school will charge you for the missing furniture when you leave, even if you replaced it with better furniture.
If you can come to an agreement with them, get it in writing!

Usually when one says semi-furnished they mean stove & refrigerator (appliances). Once in awhile if you're lucky a couch or table. When one says furnished, it means standard bed, desk, coffee table, appliances; since this is probably owned by the english school a tv as well.

Usually in those cases you ask the landlord to remove the items you do not want because if you do remove something that did belong to the landlord, you will end up paying for the item.

Be careful because the semi furnished apartment, the furniture in it might be property of the landlord or the apartment company that contracts out the apartment. When I lived in furnished apartment the items inside were proprty of the company and If they were damaged you had to pay for replacement costs!

Since it is the property of the landlord, do not you think he or she would be the one to ask? Just tell them that you do not want the furniture and would they please remove the furniture. Otherwise, you most likely will be responsible for any replacement costs should you dispose of the furniture.

Ask someone in your neighborhood how to handle sodai gomi 粗大ゴミ (large garbage).
It will depend on where you live, but you may have to go to a convenience store and buy a stamp to put on your garbage when you leave it at the drop-off area.

You could get extra money with it. Sell them! And use the money for the furniture you buy.