Provided are a compound, a method for manufacturing the compound, and a composition for forming an organic film. This compound can be cured even in an inert gas not only in air atmosphere without forming byproducts, and can form an organic under layer film that has good dry etching durability in substrate processing as well as excellent heat resistance and gap filling/planarizing characteristics of a pattern formed on a substrate. The compound has two or more structures shown by the following general formula (1-1) in the molecule, wherein Ar represents an aromatic ring or an aromatic ring thatcontains at least one nitrogen atom and/or sulfur atom optionally having a substituent, and two Ars are optionally bonded with each other to form a ring structure; the broken line represents a bond with Y; Y represents a divalent or trivalent organic group having 6 to 30 carbon atoms that contains an aromatic ring or a heteroaromatic ring optionally having a substituent, the bonds of which are located in a structure of the aromatic ring or the heteroaromatic ring; R represents a hydrogen atom or a monovalent group having 1 to 68 carbon atoms.