He thought his death was imminent.
Then, Anko asks her mother for something....
"Mother... Please remove that mask..." He said quietly as he pointed towards the mask, "If you need to burn it!" He knew, it wasn't an indiscriminate mask, which was clearly filled with evil spirits within it.
Hearing those words, at first Anko's mother didn't obey him but, when Anko explained it slowly and asked him earnestly, the mother began to worry as well. Although Anko is an unreliable daughter to him, she is still his son. It is natural that a mother has greater compassion for her biological daughter.
He immediately burned it...
He also prayed to his late grandfather in front of a photo box with incense around him, and apologized for throwing away his precious relic for the words of his son. In addition, the mother also did not want herself to be dragged into the matter of death.
"...."
The story is terrible.
It was an anko's bad condition.