Koga (古河市) is a city in Ibaraki Prefecture, Japan, situated in the southwestern part of the prefecture. As of January 2024, it has a population of approximately 137,512. The city has historical roots dating back to the Jōmon period and has developed as a significant center for iron production during the Heian period. Koga is known for its flat terrain with the Tone and Watarase Rivers flowing through it. The city has a humid continental climate, with warm summers and cool winters. Koga also has several historical sites, including the Koga Castle ruins.

💻 Koga City Official Government Website

Districts and Postal Codes in Koga

Click on the district name for the complete Japanese address, the complete English address, how to write a Japanese address, the postal code, the map location, and more.

District Postal Code
Asahicho 〒306-0012
Arakuda 〒306-0044
Isagoi Shinden 〒306-0224
Isobe 〒306-0225
Inamiya 〒306-0202
Eguchi 〒306-0105
Otsutsumi 〒306-0236
Otemachi 〒306-0032
Oyama 〒306-0052
Owada 〒306-0111
Okazato 〒306-0206
Osaki 〒306-0101
Onanuma 〒306-0226
Onna 〒306-0104
Kazuro 〒306-0211
Kamiisagoi 〒306-0223
Kamiono 〒306-0201
Kamikatata 〒306-0128
Kamihemi 〒306-0234
Kamiwada 〒306-0122
Kitatone 〒306-0213
Kitamachi 〒306-0005
Kitamanakabashi 〒306-0106
Kitayamata 〒306-0115
Kunou 〒306-0212
Keyakidaira 〒306-0055
Konosu 〒306-0041
Koya 〒306-0214
Koga 〒306-0016
Kozutsumi 〒306-0231
Gohei 〒306-0123
Komagasaki 〒306-0045
Komagome 〒306-0121
Komahane 〒306-0221
Saiwaicho 〒306-0024
Sakama 〒306-0056
Sakuramachi 〒306-0036
Sanwa 〒306-0042
Shizukamachi 〒306-0001
Shimoono 〒306-0204
Shimokatata 〒306-0127
Shimohemi 〒306-0235
Shimoyamacho 〒306-0014
Shaka 〒306-0222
Shinwada 〒306-0116
Sekido 〒306-0205
Tatsuzaki 〒306-0047
Chaya Shinden 〒306-0051
Chuocho 〒306-0033
Chozaemon Shinden 〒306-0103
Tokiwacho 〒306-0007
Torihami 〒306-0043
Nakada 〒306-0053
Nakada Shinden 〒306-0054
Nasaki 〒306-0110
Nishi Ushigaya 〒306-0233
Nishikicho 〒306-0037
Nishimachi 〒306-0038
Nishimanakabashi 〒306-0109
Nirei 〒306-0125
Hase 〒306-0035
Hasemachi 〒306-0034
Hara 〒306-0026
Haramachi 〒306-0025
Higashi 〒306-0011
Higashi Ushigaya 〒306-0232
Higashi Honcho 〒306-0013
Higashi Manakabashi 〒306-0107
Higashi Morokawa 〒306-0124
Higashi Yamata 〒306-0112
Heiwamachi 〒306-0006
Honcho 〒306-0023
Maebayashi 〒306-0216
Makinoji 〒306-0046
Matsunami 〒306-0021
Mizuumi 〒306-0215
Mizugicho 〒306-0002
Midoricho 〒306-0003
Minamicho 〒306-0015
Minami Manakabashi 〒306-0108
Miyamaecho 〒306-0031
Morokawa 〒306-0126
Yagai 〒306-0113
Yagihashi 〒306-0203
Yamata 〒306-0114
Yokoyamacho 〒306-0022
Raidencho 〒306-0004

Start with the postal code, the prefecture, the city, the district, and then the number of the block and housing unit. Then end with the person’s name.
Here’s an example of how to write a Japanese address in English.
Ginza, Chuo-ku
Mr. Taro Tanaka

For more information on how to write a Japanese address, see this article.

To type the Japanese postal code, first type the character code '3012.' Then press ALT + X and Japan's postal code symbol will appear.

To obtain an address in Koga for receiving mail, sign up for a virtual address service like MailMate. MailMate provides you with a mailing address for receiving Japanese mail and packages. MailMate can also be used for company registration in Koga, along with mail handling for Japanese properties (e.g., akiya, Airbnb, minpaku, etc.)

There are two types of PO boxes available in Koga. The first type of PO box is provided by Koga Post and is only available for individuals with a daily volume of mail. The second type of PO box is provided by private services with no limits on daily mail volume. Learn more about how to open a PO box in Japan.

Japan Post offers Standard Mail for regular letters and small parcels, typically delivered in 2-3 days. Express Mail speeds this up to 1-2 days. Registered Mail adds tracking and insurance, requiring a signature on delivery. Yu-Pack handles larger parcels with tracking and insurance, delivered in 1-3 days. Letter Pack provides flat-rate options for documents and small items, with tracking available. EMS is for international express delivery, offering fast service to over 120 countries. Non-Standard Mail covers items exceeding standard size and weight limits. Private couriers like Yamato Transport's Takkyubin offer domestic and international parcel delivery with tracking. Sagawa Express provides similar services, including same-day delivery and refrigerated shipping. International couriers like DHL, FedEx, and UPS offer express delivery with tracking and insurance. Specialized services include Cool TA-Q-BIN for refrigerated items, Yu-Mail for books and CDs, and Smart Letter for small documents. These options cover varying needs for speed, cost, and security. For more information on international shipping options, check out this article.

To send mail or packages from Koga to your home country using Japan Post, costs vary based on the service type and parcel weight. For Airmail, rates range from ¥2,050 for a 1kg parcel to ¥64,850 for a 30kg parcel. Surface Mail is cheaper, starting at ¥1,800 for a 1kg parcel to ¥21,000 for a 30kg parcel, but it takes longer. Factors affecting costs include weight, distance, and chosen service. Discounted rates are available for bulk shipments. For detailed rates and more information, visit the article here.

For sending mail and packages from Koga via Japan Post, the weight limit is 30 kg for most services. The size restrictions include a maximum combined length and girth of 3 meters (300 cm). For smaller parcels, the combined length and girth should not exceed 2 meters (200 cm). Specific dimensions and weight limits may vary depending on the service chosen (Airmail, Surface Mail, etc.). For detailed information, refer to the article here.

To print an international parcel label for Japan Post, start by creating an account on Japan Post's International Mail My Page Service. Register both sender and recipient information, then select the desired shipping service, such as EMS or Airmail. Input the shipment details, including content description, shipping date, and parcel weight. After reviewing and confirming all entered information, use the provided printer icon to print the label. For more details, refer to this article.