Frog
"Frog" in Japanese is "kaeru." , (In Japanese: 蛙/ カエル) While the writing the words are different, it is pronounced the same way you say "return/to return" (also "kaeru") (In Japanese: 帰る)
Frogs can be linked with things/or people returning to a place or origin. They are lucky to keep around so that money, friends, good things stuff which you usually see off or give away will at some point "kaeru" or come back.
Owl
In Japan, owls are symbols of good luck, mainly through a linguistic accident. The Japanese for "owl" is "fu kurou" (In Japanese: ふ くろう) , the Japanese for "hardship" is "kurou" (In Japanese: 苦労), and the Japanese for "not" is (in many cases) "fu" (In Japanese: 不). "fukurou" thus implies a life without hardship. Therefore owl symbols are often given to Japanese couples on marriage, because of the bird's auspicious association.
The four-leaf clover is an uncommon variation of the common, three-leaved clover, the ratio between finding a four-leaf to three-leaved clover is believed to be 1/10,000. According to tradition, such leaves bring good luck to their finders, especially if found accidentally. According to legend, each leaf represents something: the first is for hope, the second is for faith, the third is for love, and the fourth is for luck
(Source: Wikipedia)
