It sounds like you're referring to the Japanese phrase ( Ojisan de umeru ana ), which literally means "the hole that gets filled with middle-aged men" — often used in gacha/gaming or dark humor contexts to describe a disappointing summon result where you keep getting unwanted "old guy" characters instead of the cute/anime-style ones you wanted.
Because of its explicit nature, you won't find this on mainstream platforms like Crunchyroll ojisan de umeru ana english
The exact coiner of the phrase is unknown, but it exploded on Japanese anonymous message boards (like 2channel and later 5channel) around the mid-2000s. It emerged during the aftermath of the "Lost Decade" (1990–2000) and the subsequent "Lost 20 Years" of economic stagnation. Isekai Ojisan (Uncle from Another World): A comedy
A comedy series about a man who returns to the real world after being trapped in a fantasy world for seventeen years. ojisan de umeru ana english
Not all holes are created equal. In corporate Japan, the "ana" filled by the Ojisan usually falls into three categories:
The manga was first released in 2017 and has gained popularity worldwide. The English translation of "Ojisan de Umeru Ana" is available through various online platforms, including: