Some of the joys you'll find in Japan:
Spring
Somebody throws the main switch that turns all the flowers on.The "pink snow" of cherry blossom season.
Flower-viewing parties (sushi and beer).
Yaki imo (sweet potato) vendors.
Golden Week vacation
Summer
Rainy season ends.Beer gardens on the roofs of department stores.
Beach houses in Shonan
Summer vacation
The chime of wind bells and the varied songs of cicadas
(Ever notice how the cicadas change as the summer wears on?)
Zaru soba and iced soumen noodles
Bon Odori dances for the Festival of the Dead.
Nighttime Bonbori festivals where they float lanterns down rivers in memory of the departed.
Flavored shaved ice (kaki gori)
The calls of the nightingales.
Summer Bonus!
Ghost stories
Fireworks displays almost every weekend
Festivals in which mobs of crazed men wearing only sandals, happi coats and tiny loincloths race around bouncing a heavy wooden shrine (o-mikoshi) on their shoulders, yelling "WA-SHOI! WA-SHOI!" and having buckets of water dumped on them by spectators.
The smell of katori senko (mosquito coils)
Outdoor teahouses
Fall
The humidity dies down and the weather turns perfectBarbecues
The smell of bonfires
Sumo season
The bright colors of autumn leaves (especially the Japanese maple)
Winter
The Kotatsu: an excuse to remain immobile for hours, and the reason the Japanese use remote controls for rooms only 6x8 in sizePlastic covers over the ceiling fans on commuter trains
Mikans (tangerines)
Kimono-watching on Shichi-Go-San and "Coming of Age Day."
Those pretty white lights strung on trees in Kawasaki and Yokohama, and along Omotesando-dori in Tokyo
Mochi pounding
Traditional music played in stores and restaurants
The cool traditional decorations for Oshogatsu
Millions of festivals
Joya no Kane the eerie tolling of the temple bell at midnight, New Year's Eve
A party almost every night
Raging bargain sales, and "surprise grab bags" on sale at department stores
New Year's Vacation
All the temples and shrines are opened up, letting you see what you normally can't for the rest of the year
Miscellaneous
Garbage trucks with music boxes
The bright plastic flower/foil/tassel decorations they stick on telephone poles on shopping streets.
These change with the seasons
The subterranean fluorescent world of subway undergrounds and department store basements
Neighborly neighbors
Swept streets
Green things growing with a vengeance
Tiny shrines that pop up just about anywhere
If you can find a train station, you're never lost
Night walks
Giant carp in rivers and lakes
The abundance of birds and flowers, even in the most concrete-infested armpit of Tokyo
The weirdness of TV and billboard ads--they don't make sense, they just are
Japanese English slogans on advertisements and clothing
Mini kegs of beer sold in vending machines
Plastic food displays outside restaurants
A holiday off almost every month of the year.
Japanese TV is usually so awful you can leave the set off and get things done
Seasonal beer
An adventure always awaits