If there are multiple portions into which a single building is structurally divided that can be used as independent residences, stores, offices, warehouses, or other buildings, each of those portions may be made the subject of ownership, pursuant to the provisions of this Act.

①The term "unit ownership" as used in this Act means ownership whose subject is a portion of a building provided for in the preceding Article (excluding a portion that has been established as a common area pursuant to the provisions of Article 4, paragraph (2)).

②The term "unit owner" as used in this Act means a person with unit ownership.

③The term "exclusively-owned area" as used in this Act means a portion of a building that is the subject of unit ownership.

④The term "common area" as used in this Act means a portion of a building that is not an exclusively-owned area; an appurtenance to a building that is not a part of an exclusively-owned area; or an attached building that has been established as a common area pursuant to the provisions of Article 4, paragraph (2).

⑤The term "grounds of a building" or "building's grounds" as used in this Act means the land on which a building is located and the land that has been established as part of the grounds of the building pursuant to the provisions of Article 5, paragraph (1).

⑥The term "right to use the grounds" as used in this Act means the rights associated with the grounds of a building due to ownership of an exclusively-owned area.

All of the unit owners together may organize an association to manage the building, its grounds, and its attached facilities and, pursuant to the provisions of this Act, may hold meetings, establish bylaws, and appoint a manager. The same applies if a common area that should clearly be available for the common use of only some of the unit owners (hereinafter referred to as a "private common area") is managed by those unit owners.

①A corridor or staircase leading to multiple exclusively-owned areas, or any other portion of the building that, due to its structure, should be available for the common use of all or some of the unit owners, is not to be made the object of unit ownership.

②The bylaws may establish that a portion of a building or an attached building provided for in Article 1 is a common area. In such a case, that portion of the building or that attached building may not be asserted against a third party as a common area unless it has been registered as such.

①The bylaws may establish that a garden, passage, or other land managed or used by a unit owner as an integral part of the building or of the land on which the building is located is part of the grounds of the building.

②If land on which a building is located has become land that does not constitute that on which the building is located due to the partial destruction of the building, it is deemed to have been established as the grounds of the building by the bylaws pursuant to the provisions of the preceding paragraph. The same applies if part of the land on which a building is located has become land that does not constitute that on which the building is located due to the division of the land.

As members of the association prescribed in Article 3, unit owners must cooperate with one another so that the management of the building and its grounds and attached facilities (or, in the case referred to in the second sentence of that Article, the private common area) is carried out properly and smoothly.

①A unit owner must not perform an act that is harmful to the preservation of the building or any other act that goes against the common interest of the unit owners in connection with the management or use of the building.

②Within the scope necessary to preserve or improve an exclusively-owned area or a common area, a unit owner may request to use the exclusively-owned area of another unit owner or to use a common area not under their ownership, or to preserve these areas themselves. In such a case, if another unit owner incurs damage, the requesting unit owner must pay them compensation.

③The provisions of paragraph (1) apply mutatis mutandis to a possessor of an exclusively-owned area who is not a unit owner (hereinafter referred to as the "possessor").

④The provisions of Article 264-8 and Article 264-14 of the Civil Code (Act No. 89 of 1896) do not apply to exclusively-owned areas and common areas.

①If a unit owner does not have, or will cease to have, an address or residence in Japan (or, for a corporation, its head office or principal office; hereinafter the same applies in this paragraph and paragraph (3)), the unit owner may appoint an administrator from among persons who have an address or residence in Japan, to have the administrator perform the affairs concerning the management of the unit owner's exclusively-owned area and common areas.

②An administrator appointed pursuant to the provisions of the preceding paragraph (referred to as a "domestic administrator" in the following paragraph and paragraph (4)) has the authority to perform the following acts:

③If a unit owner has appointed a domestic administrator pursuant to the provisions of paragraph (1), and there is a manager or an incorporated management association exists, the unit owner must notify the manager or the incorporated management association without delay of the fact that they have appointed a domestic administrator, and of the name and the address or residence of the domestic administrator.

④Beyond what is prescribed in paragraph (2), the relationship between a unit owner and the domestic administrator is governed by the provisions on mandate.

①A unit owner holds a statutory lien on the debtor's unit ownership (including the rights related to the common areas and the right to use the grounds) and on the movables with which they have furnished the building in connection with a claim that involves a common area, the grounds of the building, or attached facilities of the building other than a common area, or in connection with a claim that the unit holder holds against another unit owner based on the bylaws or a meeting resolution. The same applies to a claim that the manager or incorporated management association holds against a unit owner and that involves the manager's or association's performance of their duties or work.

②The statutory lien referred to in the preceding paragraph is deemed to be a statutory lien on the expenses for common benefits in terms of its order of priority and its effect.

③The provisions of Article 319 of the Civil Code apply mutatis mutandis to the statutory lien referred to in paragraph (1).

The claims provided for in paragraph (1) of the preceding Article may be exercised against the specific successor of the unit owner who is the debtor.

If a defect in the erection or preservation of a building has caused damage to other persons, the defect is presumed to exist in the erection or preservation of the common areas.

If there is a unit owner who does not have the right to use the grounds, a person who has the right to request the removal of the owner's exclusively-owned area may request that the owner should sell and transfer their unit ownership at its market value.

①Common areas are co-owned by all the unit owners; provided, however, that a private common area is co-owned by the unit owners who should have common use of it.

②The provisions of the preceding paragraph do not preclude any provisions to the contrary in the bylaws; provided, however, that except in the case referred to in Article 27, paragraph (1), a person other than a unit owner may not be established as an owner of a common area.

③The provisions of Article 177 of the Civil Code do not apply to a common area.

If a common area is co-owned by some or all of the unit owners, co-ownership of that common area is governed by the provisions of the following Article through Article 19.

Each co-owner may use a common area in accordance with the purpose of its use.

①Each co-owner's share in a common area is proportionate to the floor area of the exclusively-owned area the co-owner owns.

②The preceding paragraph being the case, if a private common area (excluding one that is an attached building) has a floor area, the floor area of that private common area is to be divided in proportion to the floor area of the exclusive area held by each unit owner who should have common use of that private common area, and this is to be included in the calculation of the floor area of each unit owner's exclusively-owned area.

③The floor area referred to in the preceding two paragraphs is calculated as the horizontally projected area of the part that is bounded by the inner lines of the walls and other partitions.

④The provisions of the preceding three paragraphs do not preclude any provisions to the contrary in the bylaws.

①A co-owner's share in a common area follows any disposition of the exclusively-owned area they own.

②Unless otherwise provided for in this Act, a co-owner may not dispose of their share separately from the exclusively-owned area they own.

The part of the management of a private common area that is related to the interests of all unit owners or that is provided for in the bylaws under Article 31, paragraph (2) is carried out by all unit owners, and all other management of that private common area is carried out only by the unit owners who should have common use of it.