While in Japan I noticed that while the whole country is pretty dual language, many signs are sometimes Japanese only, or the Japanese is much easier to read from a distance. Many of these need to use kanji, which can be a bit of headache for people with little to no Japanese.
Therefore, I have put a little list together that I think are the most common ones to act as quick-ref or to learn of by heart if you are so inclined. You will probably want to get a phrase book, but this might help to print to fold up and then keep in your wallet for days when you want to travel light.
Note; A little bit of history for you - Japanese developed as verbal language first, with the written language being developed later. It falls into 3 ‘alphabets’- Hiragana, Katakana and Kanji. The first two are like ours where a symbol represents a sound; one, hiragana, is used for Japanese words and grammar, while Katakana is used for foreign words. Kanji however uses symbols, brought from China, which represent things, actions or concepts etc, such as “water” or “eat” or “justice”.
All are used together in Japanese and you can understand a lot more than you might think just be realising how to separate them; it helps you to find things in a dictionary, it helps you determine the tense. e.g. here the Kanji are blue, the hiragana are red and the Katakana are orange;
私はピザを食べました。- I ate Pizza.
For many kanji there are two “readings” - ‘Kun’ from the original Japanese word, and ‘On’ from the imported Chinese for the same symbol. Generally, if a kanji is on its own it is the ‘Kun’ sound, but if two kanji are linked then the ‘On’ is used, but it varies, and generally you know from experience and context. Therefore, the same kanji can appear in two words that don’t have a common sound but have the same meaning. E.g:
Hokkaido - 北海道
Kitakami - 北上
Also sometimes the same symbol has a different word depending on its context - such as a Shinto temple generally is a -ji or a -jingu, while a Buddhist one is a -dera; but both use the same kanji.
Numbers
One Ichi/Hito 一
Two Ni/Futa 二
Three San/Mi 三
Four Yon/Shi 四
Five Go/Itsu 五
Six Roku 六
Seven Nana/Shichi 七
Eight Hachi 八
Nine Kyuu 九
Ten Juu 十
Hundred Hyaku 百
Thousand Chi/sen 千
Ten Thousand Man 万
Days of week/elements
Moon/Mon/Month getsu 月
Fire/Tues ka 火
Water/Wed sui 水
Wood/Thurs moku 木
Gold/Fri kinyoubi 金
Earth/Sat doyoubi 土
Sun/Sun/day nichi 日
~day ~youbi ~曜日
*Combine together for the days of the week, so Wednesday is suiyoubi、水曜日, but you can often find them abbreviated on calendars just just the first symbol. The sharp among you will notice in Sunday that the kanji 日 appears twice, but with two different readings, as nichi and bi.
**Dates are also made using these, with month first, then day like this: 4月14日
Directions/Places
Japan Nihon 日本
Mouth/opening Guchi 口
Entrance Iriguchi 入口
Exit Deguchi 出口
North Kita/Ho 北
South Minami/Nan 南
East Higashi/To 東
West Nishi/Zai/Sai 西
Up Ue/Kami 上
Down Kuda/Shita 下
Station Eki 駅
Temple Ji/Dera 寺
Mountain Yama/San 山
Park・Garden Koen 公園
Pharmacy Yakkyoku 薬局
Post Office Yuubinkyoku 郵便局
Signs
Man Otoko 男
Woman Onna 女
Japanese Spa Onsen 温泉
Toilet Otearai お手洗い
Train Densha 電車
Smoking kitsuen 喫煙
Non-Smoking kinen 禁煙
Descriptions・Common Names
Big Oo/Dai/Tai 大
Small O/chii 小
Red Aka 赤
Blue Aoi 青
Black Kuro 黒
White Haku/Shira 白
Food
Beef/Cow Gyuu/Ushi 牛
-Bowl -Don 丼
Pork/Pig Buta 豚
Chicken/Bird Tori 鳥
Fish Sakana 魚
Fermented Tofu Miso 味噌
Meat Niku 肉
Noodle Soup Ramen ラアメン/らーめん
Battered veg/shrimp Tempura 天ぷら
Buckwheat noodles Soba そば
Sushi 寿司
Sashimi 刺身