Splitting Rent

Does the rent of an apartment change depending on single or double occupancy?

For example I’m looking at an apartment that is \100,000. If my partner lives with me, we can split the rent. That means I only pay \50,000.

However, my friend told me if a couple lives together both must pay \100,000 meaning the landlord gets \200,000 total!!!

That can’t be true, can it?

If it's a regular apartment, you are right. The landlord gets what he's advertised it for.
Things could be different if it's a house share or some other arrangement.

No, the apartment costs the list price, then is split among the occupants (though some landlords don't allow roommates/couples).

Hotels sometimes do charge by the occupant, though, even for a single room.

Some rental agreements will say for how many people the house is intended. So make sure that the contract allows 2. Then you can split the rent.

Enjoy your life in Japan!

Where do people get friends like that that spout such rubbish? Did they provide any evidence for their statement?

The fee will be specified in your contract for the apartment and may include a restriction on how many people may live there. In some cases there may be a different fee based on the number of people but it would be silly if someone tried to charge double. In my apartment building there is a base rate for solo occupancy and an extra 10,000yen per month for double occupancy - might be because utilities are included and it helps cover those costs.

generally speaking, you can't split the rent fee without the owner's permission.
1.you are the sole renter. you have to pay 100% amount. (if your partner does not pay it, you have to pay the full amount all the time.) if you are separated and you move to another place, but the ex-partner still there. you have to pay it. To terminate the contract, you have to empty the room.
2.you and your partner can be joint renters. it means that either you or your partner have to pay 100%. if you are separated and you move to another place and the ex-partner is there, the ex-partner has to pay it 100%.
or,
3.your partner becomes 連帯保証人. it means if you don't pay, the owner orders the payment to your partner automatically with 100% amount. the condition is similar to case 1. but, if you move and the ex-partner is there, the owner will charge you and/or your ex-partner. (the contract is still on-going, but the owner can charge the fee to 連帯保証人.)

therefore, there is no case in which the renting fee is splitted to 50% (or any ratios).

Why don't you use a serviced apartment? That way, the rent stays the same regardless of the amount of people lives in it. If 3 people live in it, the rent is then divided by 3. The one I use is https://metroresidences.com/