Territory of Light (光の領分, Hikari no ryōbun) is a novel by Yūko Tsushima, originally serialized in twelve parts in Gunzo from 1978 to 1979 and subsequently published by Kodansha in 1979.

In one chapter, water-proof paint is added to the roof, restricting access there, and in another, mesh is put over some windows, making less sunlight flow in.

"[10] In The Atlantic, Rowan Hisayo Buchanan noted Tsushima's careful mastery and subsequent exceeding of how autofiction, or specifically the I-novel form in Japan, is typically written and read.

"[9] Financial Times said that "Yuko Tsushima’s writing creates a studied, private world, as certain as the closure of a bedroom door" and compared the novel to The Days of Abandonment by Elena Ferrante.

[13] Star Tribune wrote: "Deceptively simple and remarkably timely, her story of a marginalized woman trying to cope with the trials of life is certain to entrance a whole new readership and pave the way for further translations of her strangely mesmerizing work.