The guest who was the "sakura"(cherry blossom) said,
"I'm a 'sakura'."
"Then I'm 'ume’ (plum blossom)."
"So where's 'matsu'(Japanese pine), then we'll have a hand."

Sakura- cherry blossom- in Japanese lingo means decoy. It sometimes means horsemeat as well.
The base of the conversation here is "Hana-Fuda", or flower cards. This is a Japanese card game with a history of hundreds of years, the cards illustrated with flowers, trees, plants, and some animals, real and imaginary. The games are basically gambling, something in the line of poker and such. There are various hands, groups of cards that, when collected, bring in high points, on par with the likes of royal straight flush, full house, etc. Sakura, ume, and matsu appear on these cards, and form hands with highest points. With sakura having the double meaning for decoy and the cards, this conversation carries an innuendo that only those familiar with Japanese and the card game would understand.

Sakura, ume, matsu, and take -bamboo- which, strangely enough is not used in Hana-Fuda, in Japan are also used to indicate high quality or high value of various objects.

Language is culture itself. The Japanese culture is based on agriculture, so much of our expressions and word usage has an agricultural basis and are often passive. Compared to that, the Western cultures have much of their basis on hunting as well as agriculture, so their expressions and word usage are more active. Hence, we call people who act as decoys, cherry blossoms.

All quite interesting, don't you think?