However, I believe you might be referring to a specific anime or manga title: "Uchi no Otouto wa Maji de Dekain Dakedo, Mi ni Konai desu."
That was the core of it. Haruki wasn’t a basketball prodigy or a stoic giant. He was a boy who loved pressed flower books, who cried at the end of Studio Ghibli movies, and whose greatest joy was curling up with their ancient, fat cat, Chibi. The problem was that Haruki hadn’t just grown; he had monstrously grown. And not a single inch of him had the aggressive confidence to match. uchi no otouto maji de dekain dakedo mi ni kona verified
The series was released as separate OVAs. While specific numbering can vary by distribution platform, it generally consists of 2 to 3 main episodes. However, I believe you might be referring to