Searching archives suggests this is not a mainstream anime or drama, but rather a from a site like Shōsetsuka ni Narō (Let’s Become a Novelist) or a niche manga anthology. The structure mirrors popular “slow-life” or “family restoration” genres:
It documents the gradual process of Hiroto becoming a "hikikomori" (shut-in) and how his dependence on his mother, Rie, intensified during this period. The Secret Relationship: Haha to Kodomobeya Oji-san no 1--- Nenkan no Nari...
Haha to Kodomobeya Oji-san no 10-nenkan no Nariyuki to, Sorekara Searching archives suggests this is not a mainstream
Haha to Kodomobeya Oji-san no 10-nenkan no Nariyuki to, Sorekara. Haha to Kodomobeya Oji-san no 1--- Nenkan no Nari...
冬。雪が舞う夜、部屋の明かりはいつもより柔らかく、空気は静かに固まる。母は台所で湯気の立つ鍋を見つめ、おじさんは窓の外の白い世界をじっと見ている。ふいに彼が、これまで誰にも話さなかった小さな後悔や、遠い故郷のことをぽつりと口にする。母は黙って耳を傾け、熱いお茶をそっと差し出す。言葉は少ないが、交わされる思いは深い。二人の存在は、もはや日々の家事や役割を超えて、互いの人生の一部となっている。
"Mother and the 'Child's Room Uncle' — 1--- Years of..."
“My mother keeps my old room exactly as it was. I (42, oji-san) now live there again after a divorce. This is the story of our one year together.”