Here are some helpful key words and phrases and their Japanese equivalents.

General Terms

postcard - hagaki

picture postcard - e-hagaki

postcards issued by the Japan Post Office - kansei hagaki

postcards made by private parties - shisei hagaki

stamp - kitte

envelope - fuuto

post office - yuubin-kyoku

date (Year, month, day) - nen-gappi

vintage postcards - furui e-hagaki

prepaid return-postcard - ofuku hagaki

picture postcard collecting - e-hagaki shu-shu

Postcard Themes

hand-colored postcards - te-saishiki e-hagaki

New Year's postcards - nengajo

summer greeting postcards - shochu omimai?

military - gunji

Russo-Japanese War - Nichiro senso

Emperor Meiji - Meiji Tenno

Emperor Taisho - Taisho Tenno

Emperor Hirohito - Showa Tenno

disaster - saigai

earthquake - jishin

flood - kozui

transportation - kotsu

airplanes - hikoki

automobiles - kuruma

trains - densha, SL, kisha

motorcycles - otobai

bicycles - jidensha

rickshaw - jin-rikisha

passenger ships - kyakusen

street scenes - machi-nami

landscape - fukei

people - jinbutsu

Japanese beauties - Nihon bijin

geisha girl - geisha

children - kodomo

kabuki actors - kabuki yakusha

nudes - nuudo

flowers - hana

expositions - hakurankai

advertising - kou-koku

art noveau - aato nuboo

overseas picture postcards (non-Japanese) - gaikoku e-hagaki

General Phrases

How much? (What's the price?) - Ikura deska?

Do you have postcards? - Hagaki arimaska?

Postcard collecting is my hobby. - E-hagaki shu-shu wa shumi des.

Are you interested in postcard collecting? - E-hagaki shu-shu ni kyomi arimaska

At the Post Office

Where's the post office? - Yubin-kyoku wa doko deska?

I want 50-yen stamps.- Goju-en kitte wo kudasai.

How much is the stamp(s)? - Kitte wa ikura desuka?

I want thirty New Year's postcards. - Sanju-mai no nengajo wo kudasai.

At the Postcard Shop

Where are the picture postcards? - E-hagaki wa doko desuka?

Do you have old (vintage) postcards? - Furui e-hagaki arimaska?