How do futarinyukyo apartments work?

My friend and I want to move in together so we can get a bigger apartment together. We are looking at places that say more than one person. I understand that 二人入居可 essentially means multiple tenants ok, but how does that work? Is there one lease that we or both on, or is is 2 separate individual lease agreements?

That simply means that "there can be two occupants/residents (in that unit)," and they are assuming that one rent agreement is signed. You will probably sign one contract, with the names of two of you listed as residents.

I guess that is for a relatively small apartment like a 1DK (one room and dining/kitchen) or 1LDK (one room, and dining/kitchen/living room, correct? Those units might have been built initially intended for a single occupancy, but if they say 二人入居可 then mean they allow two occupants, usually assuming a couple, sisters, brothers, or something like that.

As the contract is just one, even if one leaves, the full rent will remain due.

Two persons have the responsibility for full payment, individually.
If one person does not pay, the other person has to pay the full amount.

Thanks for the info. I was confused because this would appear in the listings of 2LDK and 3LDK places too.

On a side note, does this mean that any apartment the doesn't say that will not allow two people to live there together, or does just mean only one person will be on a lease?

If it is for those larger sizes of apartments, I just take it that they add that phrase to emphasize that couples, for example, are welcome, so that couples when looking for properties will notice their ads.

I don't think that other properties of larger sizes allow only single occupancy... if it is for smaller ones, like studio or 1DK, then single occupancy would be the norm, UNLESS they say 2 is OK.

And it is about "residents," not "lessees," so I don't think it has anything to do with the way the agreement will be signed.

If that is the case how are ニ人入居可 and ルームシェア可 different?