Translation guide
Menko is a traditional Japanese card-flipping game. The word refers to both the game and the cards used.
Referring to the game of menko
The most common way to refer to the game. Often written in hiragana.
I often played menko when I was a child.
Kanji form, less common but still used. Can also refer to the cards.
Menko playing has been around since the Edo period.
Referring to the cards used in the game
Since 'menko' can mean either the game or the cards, the meaning is usually clear from context. If you need to be specific, you can say めんこ遊び (menko asobi) for the game or めんこのカード (menko no kādo) for the cards.
古い面子を集めている。
I collect old menko cards.