TOKYO, Sept. 11 -- Maru, the Scottish Fold cat who captured hearts around the world with his box-loving antics, has died aged 18.

His owners announced on his YouTube channel, Mugumogu, that he "went to heaven" on September 6.

In recent weeks, Maru had grown unwell and lost his appetite. After being taken to an animal hospital, tests revealed he had a tumour. He was diagnosed with lung adenocarcinoma, a common type of lung cancer, and deteriorated quickly.

"Maru was a laid-back and calm cat, but at the very last moment he made a mad dash...

"Thank you for supporting Maru until the end," his owners wrote in a statement.

Maru rose to fame in 2008 when his ninth video - clips of him diving into cardboard boxes, his legs sticking comicall...